zoj3640 Help Me Escape

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
using namespace std;
int n,m,c[110],t[110];
double dp[20001];
bool vis[20001];
double dfs(int f){
    if(vis[f])return dp[f];
    double ans=0;
    for(int i=1;i<=n;i++){
        if(f>c[i])ans+=1.0/n*t[i];
        else ans+=1.0/n*(1+dfs(f+c[i]));
    }
    vis[f]=1;
    return dp[f]=ans;
}
int main(){
    double tmp=sqrt(5.0);
    while(scanf("%d%d",&n,&m)!=EOF){
        memset(dp,0,sizeof(dp));
        memset(vis,0,sizeof(vis));
        for(int i=1;i<=n;i++)scanf("%d",&c[i]);
        for(int i=1;i<=n;i++)t[i]=(int)((1+tmp)/2*c[i]*c[i]);
        dfs(m);
        printf("%.3lf\n",dp[m]);
    }
}

/*
    设dp[i]表示能力值为i时，逃离的期望值。
*/
#include<iostream>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<cstdio>
using namespace std;
int n,m,c[110],t[110],mx;
double dp[20001];
int main(){
    freopen("Cola.txt","r",stdin);
    double tmp=sqrt(5.0);
    while(scanf("%d%d",&n,&m)!=EOF){
        memset(dp,0,sizeof(dp));mx=0;
        for(int i=1;i<=n;i++)scanf("%d",&c[i]),mx=max(mx,c[i]);
        for(int i=1;i<=n;i++)t[i]=(int)((1+tmp)/2*c[i]*c[i]);
        for(int i=mx+mx;i>=m;i--){
            for(int j=1;j<=n;j++){
                if(i<=c[j])dp[i]+=1.0/n*(1+dp[i+c[j]]);
                if(i>c[j])dp[i]+=1.0/n*t[j];
            }
        }
        printf("%.3lf\n",dp[m]);
    }
}