60分求调T^T

#include<iostream>
#include<string>
#include<vector>
int main(){
    int n,k;
    std::string s;
    std::cin>>n>>k>>s;
    s=" "+s;
    std::vector<std::vector<long long> > num(n+1,std::vector<long long>(n+1,0));
    for(int i=1;i<=n;i++){
        long long v=0;
        for(int j=i;j<=n;j++){
            v=v*10+(s[j]-'0');
            num[i][j]=v;
        }
    }
    std::vector<std::vector<long long> > dp(n+1,std::vector<long long>(k+1,0));
    for(int i=1;i<=n;i++){
        dp[i][0]=num[1][i];
    }
    for(int t=1;t<=k;t++){
        for(int i=t+1;i<=n;i++){
            for(int j=t;j<i;j++){
                if(dp[j][t-1]*num[j+1][i]>dp[i][t]){
                    dp[i][t]=dp[j][t-1]*num[j+1][i];
                }
            }
        }
    }
    std::cout<<dp[n][k];
    return 0;
}