C++程式找出給定整數的最大可能總和
假設,我們給定兩個整數n和m,並且有k個整數元組,每個元組包含四個整數{ai, bi, ci, di}。給出四個陣列a、b、c、d,其中a[i]表示第i個元組的a值。現在,讓我們考慮一個序列dp,它有n個正整數,並且1 <= dp[1] < dp[2] < ..... < dp[n] <= m。我們定義一個度量“總和”。度量總和是在所有索引i上d[i]的總和,其中dp[b[i]] − dp[a[i]] = c[i]。如果沒有這樣的i,則總和為0。我們必須找出dp的最大可能總和。
因此,如果輸入類似於n = 4,m = 5,k = 4,a = {2, 2, 3, 5},b = {4, 3, 4, 6},c = {4, 3, 3, 4},d = {110, 20, 20, 40},則輸出將為130。
步驟
為了解決這個問題,我們將遵循以下步驟:
Define arrays A, B, C, D, and dp of sizes: 100, 100, 100, 100, 10 respectively. Define a function depthSearch(), this will take c, l, if c is same as n, then: total := 0 for initialize i := 0, when i < k, update (increase i by 1), do: if dp[B[i]] - dp[A[i]] is same as C[i], then: total := total + D[i] res := maximum of res and total return for initialize j := l, when j <= m, update (increase j by 1), do: dp[c] := j depthSearch(c + 1, j) for initialize i := 0, when i < k, update (increase i by 1), do: A[i] := a[i], B[i] := b[i], C[i] := c[i], D[i] := d[i] decrease A[i] by 1 decrease B[i] by 1 depthSearch(0, 1) return res
示例
讓我們看看以下實現以獲得更好的理解:
#include <bits/stdc++.h> using namespace std; int n, m, k, res = 0; int A[100], B[100], C[100], D[100], dp[10]; void depthSearch(int c, int l){ if(c == n){ int total = 0; for(int i = 0; i < k; i++) { if(dp[B[i]] - dp[A[i]] == C[i]) total += D[i]; } res = max(res, total); return; } for(int j = l; j <= m; j++){ dp[c] = j; depthSearch(c + 1, j); } } int solve(int a[], int b[], int c[], int d[]){ for(int i = 0; i < k; i++){ A[i] = a[i], B[i] = b[i], C[i] = c[i], D[i] = d[i]; A[i]--, B[i]--; } depthSearch(0, 1); return res; } int main() { n = 4, m = 5, k = 4; int a[] = {2, 2, 3, 5}, b[] = {4, 3, 4, 6}, c[] = {4, 3, 3, 4}, d[] = {110, 20, 20, 40}; cout<< solve(a, b, c, d); return 0; }
輸入
4, 5, 4, {2, 2, 3, 5}, {4, 3, 4, 6}, {4, 3, 3, 4}, {110, 20, 20, 40}
輸出
130
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