ACM-ICPC 2018 徐州赛区网络预赛 B BE, GE or NE

题目链接：https://nanti.jisuanke.com/t/31454

分析： dfs + 记忆化搜索 ， 0 表示 Bad ， 1 表示 Normal , 2 表示Good

代码：

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <vector>
#include <iomanip>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
#define ll long long
#define mod 100000+7
#define lowbit(x) (x&(-x))
#define mem(a,b) memset(a,b,sizeof(a))
#define FRER() freopen("in.txt","r",stdin);
#define FREW() freopen("out.txt","w",stdout);

using namespace std;
const int maxn = 10000 + 7, inf = 0x3f3f3f3f;

int a[maxn],b[maxn],c[maxn];
int dp[maxn][200+7];
map<int,int>id;
int n,s,k,l,tot=0;
int dfs(int pos,int u){
    if(pos==n+1){
        if(u>=k) return 2;
        else if(u>l) return 1;
        else return 0;
    }
    if(dp[pos][id[u]]!=-1) return dp[pos][id[u]];
    if(pos&1){
        int tmp = 0;
        if(a[pos]!=0) tmp = max(tmp,dfs(pos+1,min(u+a[pos],100)));
        if(b[pos]!=0) tmp = max(tmp,dfs(pos+1,max(u+b[pos],-100)));
        if(c[pos]!=0) tmp = max(tmp,dfs(pos+1,-u));
        return dp[pos][id[u]] = tmp;
    }else{
        int tmp = 2;
        if(a[pos]!=0) tmp = min(tmp,dfs(pos+1,min(u+a[pos],100)));
        if(b[pos]!=0) tmp = min(tmp,dfs(pos+1,max(u+b[pos],-100)));
        if(c[pos]!=0) tmp = min(tmp,dfs(pos+1,-u));
        return dp[pos][id[u]] = tmp;
    }
}
int main()
{
    //FRER();
    scanf("%d%d%d%d",&n,&s,&k,&l);
    for(int i=1;i<=n;i++){
        scanf("%d%d%d",&a[i],&b[i],&c[i]);
        b[i] = -b[i];
    }
    for(int i=-100;i<=100;i++)
        id[i] = ++tot;
    mem(dp,-1);
    int ans = dfs(1,s);
    if(ans == 2) printf("Good Ending\n");
    if(ans == 1) printf("Normal Ending\n");
    if(ans == 0) printf("Bad Ending\n");
    return 0;
}