zoj 2297 Survival

#include <cstdio>#include <cstring>#include <string>#include <iostream>#include <algorithm>#include <vector>using namespace std;const long long N = 22;const int inf = 0x3f3f3f3f;int dp[1<<N];pair<int,int> p[N];int main(){    int n,boss;    while(~scanf("%d",&n) && n)    {        n--;        for(int i=0;i<n;i++)        { int x,y; scanf("%d%d",&x,&y); p[i]=make_pair(x,y);        }        scanf("%d",&boss);        memset(dp,0,sizeof(dp));        int ans = 0;        dp[0]=100;        for(int st=1;st<(1<<n);st++)        { dp[st]=-inf;   for(int j=0;j<n;j++)     if(st&(1<<j)&&dp[st&~(1<<j)]>=p[j].first)     {         dp[st]=max(dp[st],dp[st&~(1<<j)]-p[j].first+p[j].second);         if(dp[st]>100)  dp[st]=100;     }        }        if(dp[(1<<n)-1]>=boss) puts("clear!!!");        else puts("try again");    }    return 0;}