google code jam 2014 RC_C

来源：互联网发布：数据恢复中心赵力编辑：程序博客网时间：2024/05/16 18:33

一道很灵活的贪心小题木，我也是看了官方题解才想到的- -！！一般都用最大流做的。

枚举+贪心构造法

#include <cstdio>#include <cstring>using namespace std;int T,N;char com[1001][2];int id[1001];bool in[5001];bool oc[5001];int sot[5001];int ID=2001;bool simulate(int n){for(int i=0; i<n; ++i){bool sta=0;memset(oc,0,sizeof(oc));for(int j=0; j<N; ++j){if(com[j][0]=='L'&&oc[id[j]]==0&&id[j]&&in[id[j]]==0){in[id[j]]=1;sta=1;break;}oc[id[j]]=1;}if(sta==0){in[ID++]=1;}}for(int i=0; i<N; ++i){if(com[i][0]=='E'){if(id[i]==0){bool sta=0;memset(oc,0,sizeof(oc));for(int j=i+1; j<N; ++j){if(com[j][0]=='L'&&oc[id[j]]==0&&id[j]&&in[id[j]]==0){in[id[j]]=1;sta=1;break;}oc[id[j]]=1;}if(sta==0){in[ID++]=1;}}else{if(in[id[i]]){return false;}else{in[id[i]]=1;}}}else{if(id[i]==0){bool sta=0;memset(oc,0,sizeof(oc));for(int j=i+1; j<N; ++j){if(com[j][0]=='E'&&oc[id[j]]==0&&id[j]&&in[id[j]]){in[id[j]]=0;sta=1;break;}oc[id[j]]=1;}if(sta==0){memset(oc,0,sizeof(oc));for(int j=i+1; j<N; ++j){if(id[j]){oc[id[j]]=1;}}for(int j=1; j<=5000; ++j){if(in[j]&&oc[j]==0){in[j]=0;sta=1;break;}}}if(sta==0){memset(sot,0,sizeof(sot));for(int j=N-1; j>i; --j){if(com[j][0]=='L'&&in[id[j]]){sot[id[j]]=j;}}int tmp=0,iid=-1;for(int j=1; j<=5000; ++j){if(sot[j]>tmp){iid=j; tmp=sot[j];}}if(iid!=-1){in[iid]=0; sta=1;}}if(sta==0) return false;}else{if(in[id[i]]==0){return false;}else{in[id[i]]=0;}}}}return true;}int main(){freopen("C-large-practice.in","r",stdin);freopen("c2.out","w",stdout);scanf("%d",&T);for(int cas=1; cas<=T; ++cas){scanf("%d",&N);int icnt=0,ocnt=0;for(int i=0; i<N; ++i){scanf("%s %d",com+i,id+i);if(com[i][0]=='E') ++icnt;else ++ocnt;}printf("Case #%d: ",cas);bool end=0;for(int i=0; i<=N; ++i){ID=2001;memset(in,0,sizeof(in));if(simulate(i)){printf("%d\n",icnt+i-ocnt);end=1;break;}//puts("CRIME TIME");}if(end==0){puts("CRIME TIME");}}}

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