POJ 1651 Multiplication Puzzle(区间DP)

Multiplication Puzzle

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

int n,a[105],
dp[105][105], i, j, k, l;

int main(){

    //freopen("data.in", "r", stdin);
    while(~scanf("%d",&n)){
        for(i = 1; i <= n; i++)
            scanf("%d", &a[i]);

        memset(dp, 0x3f3f3f3f, sizeof(dp));
        for(int i = 1; i <= n; i++)//1张牌没意义
            dp[i][i] = 0;

        for(l = 2; l <= n-1; l++){//长度从2开始枚举,最后一张牌不能动
            for(i = 2; i <= n-l+1; i++){
                j = i+l-1;

                dp[i][j] = 0x3f3f3f3f;
                for(k = i; k < j; k++)//枚举中点
                    dp[i][j] = min(dp[i][j],dp[i][k]+dp[k+1][j]+a[i-1]*a[k]*a[j]);
            }
        }
        printf("%d\n",dp[2][n]);
    }

    return 0;
}