一定要初始化~

不开long long建祖宗~

#include<bits/stdc++.h>
using namespace std;
vector<int> f[101][101];
long long w[101];
vector<int> add(vector<int> a,vector<int>b){
    vector<int> c;
    int t=0;
    for(int i=0;i<a.size()||i<b.size();i++){
        if(i<a.size()) t+=a[i];
        if(i<b.size()) t+=b[i];
        c.push_back(t%10);
        t/=10;
    }
    if(t>0) c.push_back(t);
    return c;
}
vector<int> mul(vector<int> a,long long b){
    vector<int> c;
    long long t=0;
    for(int i=0;i<a.size()||t;i++){
        if(i<a.size()){
            t+=a[i]*(long long)b;
        }
        //cout<<":"<<t<<endl;
        c.push_back(t%10);
        t/=10;
    }
    return c;
}
vector<int> min_v(vector<int> a,vector<int> b){
    if(a.size()<b.size()){
        return a;
    }
    if(a.size()>b.size()){
        return b;
    }
    for(int i=a.size()-1;i>=0;i--){
        if(a[i]>b[i]) return b;
        else if(a[i]<b[i]) return a;
    }
    return a;
}
int main(){
    //memset(f,0x3f,sizeof f);
    int n;
    cin>>n;
    //vector<int> a = vector<int>(1,3);
    //int b=5;
    //vector<int> c = mul(a,b);
    //for(int i=c.size()-1;i>=0;i--) cout<<c[i];
    //cout<<endl;
    for(int i=1;i<=n;i++){
        cin>>w[i];
    }

    for(int len=3;len<=n;len++){
        for(int l=1;l+len-1<=n;l++){

            int r=l+len-1;
            f[l][r]=vector<int>(55,1);
            for(int k=l+1;k<=r-1;k++){
                vector<int> t;
                t.clear();
                t.push_back(w[l]);
                t=mul(t,w[k]);
                t=mul(t,w[r]);
                t=add(t,f[l][k]);
                t=add(t,f[k][r]);
                f[l][r]=min_v(f[l][r],t);

            }
        }
    }

    for(int i=f[1][n].size()-1;i>=0;i--)
        cout<<f[1][n][i];
    cout<<endl;
}