题目链接:点击打开链
题意:
给定一个数组,每次能够选择内部的一个数 i 消除,获得的价值就是 a[i-1] * a[i] * a[i+1]
问最小价值
思路:
dp[l,r] = min( dp[l, i] + dp[i, r] + a[l] * a[i] * a[r]);
#include <cstdio> #include <iostream> #include <algorithm> #include <queue> #include <cstring> #include <cmath> using namespace std; const int N = 105; const int inf = 100000000; int a[N], dp[N][N], n; int dfs(int l, int r){//返回 把区间l,r合并,最后仅仅剩下a[l]和a[r]能获得的最小价值 if(l > r) return 0; if(dp[l][r] != -1)return dp[l][r];//若区间[l,r]已经计算过则不再计算 if(l == r || l+1 == r) return dp[l][r] = 0;//仅仅有1个或者2个元素则价值是0 int ans = inf; for(int i = l+1; i < r; i++) ans = min(ans, a[i] * a[l] * a[r] + dfs(l, i) + dfs(i, r)); return dp[l][r] = ans; } int main(){ while(cin>>n){ for(int i = 1; i <= n; i++)scanf("%d", &a[i]); memset(dp, -1, sizeof dp); cout<<dfs(1, n)<<endl; } return 0; }