طباعة الحد الأقصى للمبلغ اللاحق المتزايد
تتمثل مشكلة الحد الأقصى لمجموع التسلسل الفرعي في العثور على الحد الأقصى لمجموع التسلسل الفرعي لتسلسل معين بحيث يتم فرز جميع عناصر التسلسل الفرعي بترتيب متزايد.
أمثلة:
Input: [1 101 2 3 100 4 5]
Output: [1 2 3 100]
Input: [3 4 5 10]
Output: [3 4 5 10]
Input: [10 5 4 3]
Output: [10]
Input: [3 2 6 4 5 1]
Output: [3 4 5]في المقالة السابقة ناقشنا مشكلة الحد الأقصى للمجموع المتزايد للتسلسل اللاحق. ومع ذلك، فإن المنشور يغطي فقط الكود المتعلق بإيجاد الحد الأقصى لمجموع التسلسل اللاحق المتزايد ولكن ليس لبناء التسلسل اللاحق. سنناقش في هذا المنشور كيفية إنشاء الحد الأقصى للمجموع المتزايد للتسلسل نفسه.
دع arr[0..n-1] يكون مصفوفة الإدخال. نحن نحدد المتجه L بحيث يكون L[i] في حد ذاته متجهًا يخزن الحد الأقصى للمجموع المتزايد للتسلسل arr[0..i] الذي ينتهي بـ arr[i]. لذلك يمكن كتابة الفهرس i L[i] بشكل متكرر كـ
L[0] = {arr[0]}
L[i] = {MaxSum(L[j])} + arr[i] where j < i and arr[j] < arr[i]
= arr[i] if there is no j such that arr[j] < arr[i]
على سبيل المثال للمصفوفة [3 2 6 4 5 1]L[0]: 3
L[1]: 2
L[2]: 3 6
L[3]: 3 4
L[4]: 3 4 5
L[5]: 1C++
وفيما يلي تنفيذ الفكرة المذكورة أعلاه -Java/* Dynamic Programming solution to construct Maximum Sum Increasing Subsequence */ #include#include using namespace std ; // Utility function to calculate sum of all // vector elements int findSum ( vector < int > arr ) { int sum = 0 ; for ( int i : arr ) sum += i ; return sum ; } // Function to construct Maximum Sum Increasing // Subsequence void printMaxSumIS ( int arr [] int n ) { // L[i] - The Maximum Sum Increasing // Subsequence that ends with arr[i] vector < vector < int > > L ( n ); // L[0] is equal to arr[0] L [ 0 ]. push_back ( arr [ 0 ]); // start from index 1 for ( int i = 1 ; i < n ; i ++ ) { // for every j less than i for ( int j = 0 ; j < i ; j ++ ) { /* L[i] = {MaxSum(L[j])} + arr[i] where j < i and arr[j] < arr[i] */ if (( arr [ i ] > arr [ j ]) && ( findSum ( L [ i ]) < findSum ( L [ j ]))) L [ i ] = L [ j ]; } // L[i] ends with arr[i] L [ i ]. push_back ( arr [ i ]); // L[i] now stores Maximum Sum Increasing // Subsequence of arr[0..i] that ends with // arr[i] } vector < int > res = L [ 0 ]; // find max for ( vector < int > x : L ) if ( findSum ( x ) > findSum ( res )) res = x ; // max will contain result for ( int i : res ) cout < < i < < ' ' ; cout < < endl ; } // Driver Code int main () { int arr [] = { 3 2 6 4 5 1 }; int n = sizeof ( arr ) / sizeof ( arr [ 0 ]); // construct and print Max Sum IS of arr printMaxSumIS ( arr n ); return 0 ; } Python/* Dynamic Programming solution to construct Maximum Sum Increasing Subsequence */ import java.util.* ; class GFG { // Utility function to calculate sum of all // vector elements static int findSum ( Vector < Integer > arr ) { int sum = 0 ; for ( int i : arr ) sum += i ; return sum ; } // Function to construct Maximum Sum Increasing // Subsequence static void printMaxSumIs ( int [] arr int n ) { // L[i] - The Maximum Sum Increasing // Subsequence that ends with arr[i] @SuppressWarnings ( 'unchecked' ) Vector < Integer >[] L = new Vector [ n ] ; for ( int i = 0 ; i < n ; i ++ ) L [ i ] = new Vector <> (); // L[0] is equal to arr[0] L [ 0 ] . add ( arr [ 0 ] ); // start from index 1 for ( int i = 1 ; i < n ; i ++ ) { // for every j less than i for ( int j = 0 ; j < i ; j ++ ) { /* * L[i] = {MaxSum(L[j])} + arr[i] where j < i and arr[j] < arr[i] */ if (( arr [ i ] > arr [ j ] ) && ( findSum ( L [ i ] ) < findSum ( L [ j ] ))) { for ( int k : L [ j ] ) if ( ! L [ i ] . contains ( k )) L [ i ] . add ( k ); } } // L[i] ends with arr[i] L [ i ] . add ( arr [ i ] ); // L[i] now stores Maximum Sum Increasing // Subsequence of arr[0..i] that ends with // arr[i] } Vector < Integer > res = new Vector <> ( L [ 0 ] ); // res = L[0]; // find max for ( Vector < Integer > x : L ) if ( findSum ( x ) > findSum ( res )) res = x ; // max will contain result for ( int i : res ) System . out . print ( i + ' ' ); System . out . println (); } // Driver Code public static void main ( String [] args ) { int [] arr = { 3 2 6 4 5 1 }; int n = arr . length ; // construct and print Max Sum IS of arr printMaxSumIs ( arr n ); } } // This code is contributed by // sanjeev2552C## Dynamic Programming solution to construct # Maximum Sum Increasing Subsequence */ # Utility function to calculate sum of all # vector elements def findSum ( arr ): summ = 0 for i in arr : summ += i return summ # Function to construct Maximum Sum Increasing # Subsequence def printMaxSumIS ( arr n ): # L[i] - The Maximum Sum Increasing # Subsequence that ends with arr[i] L = [[] for i in range ( n )] # L[0] is equal to arr[0] L [ 0 ] . append ( arr [ 0 ]) # start from index 1 for i in range ( 1 n ): # for every j less than i for j in range ( i ): # L[i] = {MaxSum(L[j])} + arr[i] # where j < i and arr[j] < arr[i] if (( arr [ i ] > arr [ j ]) and ( findSum ( L [ i ]) < findSum ( L [ j ]))): for e in L [ j ]: if e not in L [ i ]: L [ i ] . append ( e ) # L[i] ends with arr[i] L [ i ] . append ( arr [ i ]) # L[i] now stores Maximum Sum Increasing # Subsequence of arr[0..i] that ends with # arr[i] res = L [ 0 ] # find max for x in L : if ( findSum ( x ) > findSum ( res )): res = x # max will contain result for i in res : print ( i end = ' ' ) # Driver Code arr = [ 3 2 6 4 5 1 ] n = len ( arr ) # construct and prMax Sum IS of arr printMaxSumIS ( arr n ) # This code is contributed by Mohit KumarJavaScript/* Dynamic Programming solution to construct Maximum Sum Increasing Subsequence */ using System ; using System.Collections.Generic ; class GFG { // Utility function to calculate sum of all // vector elements static int findSum ( List < int > arr ) { int sum = 0 ; foreach ( int i in arr ) sum += i ; return sum ; } // Function to construct Maximum Sum Increasing // Subsequence static void printMaxSumIs ( int [] arr int n ) { // L[i] - The Maximum Sum Increasing // Subsequence that ends with arr[i] List < int > [] L = new List < int > [ n ]; for ( int i = 0 ; i < n ; i ++ ) L [ i ] = new List < int > (); // L[0] is equal to arr[0] L [ 0 ]. Add ( arr [ 0 ]); // start from index 1 for ( int i = 1 ; i < n ; i ++ ) { // for every j less than i for ( int j = 0 ; j < i ; j ++ ) { /* * L[i] = {MaxSum(L[j])} + arr[i] where j < i and arr[j] < arr[i] */ if (( arr [ i ] > arr [ j ]) && ( findSum ( L [ i ]) < findSum ( L [ j ]))) { foreach ( int k in L [ j ]) if ( ! L [ i ]. Contains ( k )) L [ i ] . Add ( k ); } } // L[i] ends with arr[i] L [ i ]. Add ( arr [ i ]); // L[i] now stores Maximum Sum Increasing // Subsequence of arr[0..i] that ends with // arr[i] } List < int > res = new List < int > ( L [ 0 ]); // res = L[0]; // find max foreach ( List < int > x in L ) if ( findSum ( x ) > findSum ( res )) res = x ; // max will contain result foreach ( int i in res ) Console . Write ( i + ' ' ); Console . WriteLine (); } // Driver Code public static void Main ( String [] args ) { int [] arr = { 3 2 6 4 5 1 }; int n = arr . Length ; // construct and print Max Sum IS of arr printMaxSumIs ( arr n ); } } // This code is contributed by PrinciRaj1992< script > /* Dynamic Programming solution to construct Maximum Sum Increasing Subsequence */ // Utility function to calculate sum of all // vector elements function findSum ( arr ) { let sum = 0 ; for ( let i = 0 ; i < arr . length ; i ++ ) sum += arr [ i ]; return sum ; } // Function to construct Maximum Sum Increasing // Subsequence function printMaxSumIs ( arr n ) { // L[i] - The Maximum Sum Increasing // Subsequence that ends with arr[i] let L = new Array ( n ); for ( let i = 0 ; i < n ; i ++ ) L [ i ] = []; // L[0] is equal to arr[0] L [ 0 ]. push ( arr [ 0 ]); // start from index 1 for ( let i = 1 ; i < n ; i ++ ) { // for every j less than i for ( let j = 0 ; j < i ; j ++ ) { /* * L[i] = {MaxSum(L[j])} + arr[i] where j < i and arr[j] < arr[i] */ if (( arr [ i ] > arr [ j ]) && ( findSum ( L [ i ]) < findSum ( L [ j ]))) { for ( let k = 0 ; k < L [ j ]. length ; k ++ ) if ( ! L [ i ]. includes ( L [ j ][ k ])) L [ i ]. push ( L [ j ][ k ]); } } // L[i] ends with arr[i] L [ i ]. push ( arr [ i ]); // L[i] now stores Maximum Sum Increasing // Subsequence of arr[0..i] that ends with // arr[i] } let res = L [ 0 ]; // res = L[0]; // find max for ( let x = 0 ; x < L . length ; x ++ ) if ( findSum ( L [ x ]) > findSum ( res )) res = L [ x ]; // max will contain result for ( let i = 0 ; i < res . length ; i ++ ) document . write ( res [ i ] + ' ' ); document . write ( '
' ); } // Driver Code let arr = [ 3 2 6 4 5 1 ]; let n = arr . length ; // construct and print Max Sum IS of arr printMaxSumIs ( arr n ); // This code is contributed by unknown2108 < /script>
الإخراج3 4 5
يمكننا تحسين حل DP أعلاه عن طريق إزالة وظيفة findSum(). بدلًا من ذلك، يمكننا الاحتفاظ بمتجه/مصفوفة أخرى لتخزين مجموع الحد الأقصى للتسلسل المتزايد الذي ينتهي بـ arr[i].تعقيد الوقت من حل البرمجة الديناميكية أعلاه هو O(n 2 ).
مساحة مساعدة المستخدم في البرنامج هو O(n 2 ).النهج 2: ( استخدام البرمجة الديناميكية باستخدام مساحة O(N).
غطى النهج المذكور أعلاه كيفية إنشاء الحد الأقصى للمجموع المتزايد في O(N 2 ) الوقت و O(N 2 ) فضاء. في هذا النهج، سنقوم بتحسين تعقيد الفضاء وبناء الحد الأقصى للمجموع المتزايد في O(N 2 ) الوقت ومساحة O(N).
- دع arr[0..n-1] يكون مصفوفة الإدخال.
- نحدد متجهًا للأزواج L بحيث يقوم L[i] أولاً بتخزين الحد الأقصى للتسلسل المتزايد لـ arr[0..i] الذي ينتهي بـ arr[i] وL[i].sec يخزن فهرس العنصر السابق المستخدم لإنشاء المجموع.
- بما أن العنصر الأول لا يحتوي على أي عنصر سابق، فإن فهرسه سيكون -1 في L[0].
على سبيل المثال
array = [3 2 6 4 5 1]
L[0]: {3 -1}
L[1]: {2 1}
L[2]: {9 0}
L[3]: {7 0}
L[4]: {12 3}
L[5]: {1 5}كما نرى أعلاه، فإن قيمة الحد الأقصى للتسلسل الفرعي المتزايد هي 12. لإنشاء التسلسل اللاحق الفعلي، سنستخدم الفهرس المخزن في L[i].ثانية. خطوات بناء اللاحقة موضحة أدناه:
- في نتيجة المتجهات، قم بتخزين قيمة العنصر حيث تم العثور على الحد الأقصى للمجموع المتزايد (أي في currIndex = 4). لذا سنضيف arr[currIndex] إلى متجه النتيجة.
- قم بتحديث currIndex إلى L[currIndex].ثانية وكرر الخطوة 1 حتى لا يصبح currIndex -1 أو لا يتغير (أي currIndex == PreviousIndex).
- عرض عناصر متجه النتيجة بترتيب عكسي.
وفيما يلي تنفيذ الفكرة المذكورة أعلاه:
C++14 /* Dynamic Programming solution to construct Maximum Sum Increasing Subsequence */ #include using namespace std ; // Function to construct and print the Maximum Sum // Increasing Subsequence void constructMaxSumIS ( vector < int > arr int n ) { // L[i] stores the value of Maximum Sum Increasing // Subsequence that ends with arr[i] and the index of // previous element used to construct the Subsequence vector < pair < int int > > L ( n ); int index = 0 ; for ( int i : arr ) { L [ index ] = { i index }; index ++ ; } // Set L[0].second equal to -1 L [ 0 ]. second = -1 ; // start from index 1 for ( int i = 1 ; i < n ; i ++ ) { // for every j less than i for ( int j = 0 ; j < i ; j ++ ) { if ( arr [ i ] > arr [ j ] and L [ i ]. first < arr [ i ] + L [ j ]. first ) { L [ i ]. first = arr [ i ] + L [ j ]. first ; L [ i ]. second = j ; } } } int maxi = INT_MIN currIndex track = 0 ; for ( auto p : L ) { if ( p . first > maxi ) { maxi = p . first ; currIndex = track ; } track ++ ; } // Stores the final Subsequence vector < int > result ; // Index of previous element // used to construct the Subsequence int prevoiusIndex ; while ( currIndex >= 0 ) { result . push_back ( arr [ currIndex ]); prevoiusIndex = L [ currIndex ]. second ; if ( currIndex == prevoiusIndex ) break ; currIndex = prevoiusIndex ; } for ( int i = result . size () - 1 ; i >= 0 ; i -- ) cout < < result [ i ] < < ' ' ; } // Driver Code int main () { vector < int > arr = { 1 101 2 3 100 4 5 }; int n = arr . size (); // Function call constructMaxSumIS ( arr n ); return 0 ; }
Java // Dynamic Programming solution to construct // Maximum Sum Increasing Subsequence import java.util.* ; import java.awt.Point ; class GFG { // Function to construct and print the Maximum Sum // Increasing Subsequence static void constructMaxSumIS ( List < Integer > arr int n ) { // L.get(i) stores the value of Maximum Sum Increasing // Subsequence that ends with arr.get(i) and the index of // previous element used to construct the Subsequence List < Point > L = new ArrayList < Point > (); int index = 0 ; for ( int i : arr ) { L . add ( new Point ( i index )); index ++ ; } // Set L[0].second equal to -1 L . set ( 0 new Point ( L . get ( 0 ). x - 1 )); // Start from index 1 for ( int i = 1 ; i < n ; i ++ ) { // For every j less than i for ( int j = 0 ; j < i ; j ++ ) { if ( arr . get ( i ) > arr . get ( j ) && L . get ( i ). x < arr . get ( i ) + L . get ( j ). x ) { L . set ( i new Point ( arr . get ( i ) + L . get ( j ). x j )); } } } int maxi = - 100000000 currIndex = 0 track = 0 ; for ( Point p : L ) { if ( p . x > maxi ) { maxi = p . x ; currIndex = track ; } track ++ ; } // Stores the final Subsequence List < Integer > result = new ArrayList < Integer > (); // Index of previous element // used to construct the Subsequence int prevoiusIndex ; while ( currIndex >= 0 ) { result . add ( arr . get ( currIndex )); prevoiusIndex = L . get ( currIndex ). y ; if ( currIndex == prevoiusIndex ) break ; currIndex = prevoiusIndex ; } for ( int i = result . size () - 1 ; i >= 0 ; i -- ) System . out . print ( result . get ( i ) + ' ' ); } // Driver Code public static void main ( String [] s ) { List < Integer > arr = new ArrayList < Integer > (); arr . add ( 1 ); arr . add ( 101 ); arr . add ( 2 ); arr . add ( 3 ); arr . add ( 100 ); arr . add ( 4 ); arr . add ( 5 ); int n = arr . size (); // Function call constructMaxSumIS ( arr n ); } } // This code is contributed by rutvik_56
Python # Dynamic Programming solution to construct # Maximum Sum Increasing Subsequence import sys # Function to construct and print the Maximum Sum # Increasing Subsequence def constructMaxSumIS ( arr n ) : # L[i] stores the value of Maximum Sum Increasing # Subsequence that ends with arr[i] and the index of # previous element used to construct the Subsequence L = [] index = 0 for i in arr : L . append ([ i index ]) index += 1 # Set L[0].second equal to -1 L [ 0 ][ 1 ] = - 1 # start from index 1 for i in range ( 1 n ) : # for every j less than i for j in range ( i ) : if ( arr [ i ] > arr [ j ] and L [ i ][ 0 ] < arr [ i ] + L [ j ][ 0 ]) : L [ i ][ 0 ] = arr [ i ] + L [ j ][ 0 ] L [ i ][ 1 ] = j maxi currIndex track = - sys . maxsize 0 0 for p in L : if ( p [ 0 ] > maxi ) : maxi = p [ 0 ] currIndex = track track += 1 # Stores the final Subsequence result = [] while ( currIndex >= 0 ) : result . append ( arr [ currIndex ]) prevoiusIndex = L [ currIndex ][ 1 ] if ( currIndex == prevoiusIndex ) : break currIndex = prevoiusIndex for i in range ( len ( result ) - 1 - 1 - 1 ) : print ( result [ i ] end = ' ' ) arr = [ 1 101 2 3 100 4 5 ] n = len ( arr ) # Function call constructMaxSumIS ( arr n ) # This code is contributed by divyeshrabadiya07
C# /* Dynamic Programming solution to construct Maximum Sum Increasing Subsequence */ using System ; using System.Collections.Generic ; class GFG { // Function to construct and print the Maximum Sum // Increasing Subsequence static void constructMaxSumIS ( List < int > arr int n ) { // L[i] stores the value of Maximum Sum Increasing // Subsequence that ends with arr[i] and the index of // previous element used to construct the Subsequence List < Tuple < int int >> L = new List < Tuple < int int >> (); int index = 0 ; foreach ( int i in arr ) { L . Add ( new Tuple < int int > ( i index )); index ++ ; } // Set L[0].second equal to -1 L [ 0 ] = new Tuple < int int > ( L [ 0 ]. Item1 - 1 ); // start from index 1 for ( int i = 1 ; i < n ; i ++ ) { // for every j less than i for ( int j = 0 ; j < i ; j ++ ) { if ( arr [ i ] > arr [ j ] && L [ i ]. Item1 < arr [ i ] + L [ j ]. Item1 ) { L [ i ] = new Tuple < int int > ( arr [ i ] + L [ j ]. Item1 j ); } } } int maxi = Int32 . MinValue currIndex = 0 track = 0 ; foreach ( Tuple < int int > p in L ) { if ( p . Item1 > maxi ) { maxi = p . Item1 ; currIndex = track ; } track ++ ; } // Stores the final Subsequence List < int > result = new List < int > (); // Index of previous element // used to construct the Subsequence int prevoiusIndex ; while ( currIndex >= 0 ) { result . Add ( arr [ currIndex ]); prevoiusIndex = L [ currIndex ]. Item2 ; if ( currIndex == prevoiusIndex ) break ; currIndex = prevoiusIndex ; } for ( int i = result . Count - 1 ; i >= 0 ; i -- ) Console . Write ( result [ i ] + ' ' ); } static void Main () { List < int > arr = new List < int > ( new int [] { 1 101 2 3 100 4 5 }); int n = arr . Count ; // Function call constructMaxSumIS ( arr n ); } } // This code is contributed by divyesh072019
JavaScript < script > // Dynamic Programming solution to construct // Maximum Sum Increasing Subsequence // Function to construct and print the Maximum Sum // Increasing Subsequence function constructMaxSumIS ( arr n ){ // L[i] stores the value of Maximum Sum Increasing // Subsequence that ends with arr[i] and the index of // previous element used to construct the Subsequence let L = [] let index = 0 for ( let i of arr ){ L . push ([ i index ]) index += 1 } // Set L[0].second equal to -1 L [ 0 ][ 1 ] = - 1 // start from index 1 for ( let i = 1 ; i < n ; i ++ ){ // for every j less than i for ( let j = 0 ; j < i ; j ++ ){ if ( arr [ i ] > arr [ j ] && L [ i ][ 0 ] < arr [ i ] + L [ j ][ 0 ]){ L [ i ][ 0 ] = arr [ i ] + L [ j ][ 0 ] L [ i ][ 1 ] = j } } } let maxi = Number . MIN_VALUE currIndex = 0 track = 0 for ( let p of L ){ if ( p [ 0 ] > maxi ){ maxi = p [ 0 ] currIndex = track } track += 1 } // Stores the final Subsequence let result = [] while ( currIndex >= 0 ){ result . push ( arr [ currIndex ]) let prevoiusIndex = L [ currIndex ][ 1 ] if ( currIndex == prevoiusIndex ) break currIndex = prevoiusIndex } for ( let i = result . length - 1 ; i >= 0 ; i -- ) document . write ( result [ i ] ' ' ) } let arr = [ 1 101 2 3 100 4 5 ] let n = arr . length // Function call constructMaxSumIS ( arr n ) // This code is contributed by shinjanpatra < /script>
الإخراج
1 2 3 100
تعقيد الوقت: على 2 )
تعقيد الفضاء: على)