蓝桥杯：矩阵乘法（区间DP）

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long LL;
 4 const LL INF = 100000000000000000LL;
 5 LL num[1010];
 6 LL dp[1010][1010];
 7 int main() {
 8     LL ans = 0;
 9     int n; cin >> n;
10     for(int i = 0; i <= n; i++) scanf("%lld", &num[i]), dp[i][i] = num[i];
11     for(int len = 2; len <= n; len++) {
12         for(int l = 0; l + len <= n; l++) {
13             int r = l + len;
14             dp[l][r] = INF;
15             for(int k = l + 1; k < r; k++) {
16                 dp[l][r] = min(dp[l][r], dp[l][k] + dp[k][r] + num[l] * num[k] * num[r]);
17             }
18         }
19     }
20     cout << dp[0][n] << endl;
21     return 0;
22 }