石子归并(codevs_1048)——区间dp

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
inline int read(){
    int t=1,num=0;char c=getchar();
    while(c>‘9‘||c<‘0‘){if(c==‘-‘)t=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){num=num*10+c-‘0‘;c=getchar();}
    return num*t;
}
const int N=110;
int a[N],s[N],n,f[N][N];
int main()
{
    n=read();
    for(int i=1;i<=n;i++)
        a[i]=read(),s[i]=s[i-1]+a[i];
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            f[i][j]=(i==j?0:1e9);
    for(int i=n-1;i>=1;i--)
      for(int j=i+1;j<=n;j++)
        for(int k=i;k<j;k++)
          f[i][j]=min(f[i][j],f[i][k]+f[k+1][j]+s[j]-s[i-1]);
    printf("%d",f[1][n]);
    return 0;
}