HDU 2668

不多说了。。虽然使水题，但做了比较久

#include<stdio.h>#include<string.h>char a[10000005];int main(){int n;int flag[200];while(scanf("%d",&n)!=EOF){getchar();memset(flag,0,sizeof(flag));int i,j,begin=0,last,max=-9999,res_begin=0,res_last=0;scanf("%s",a);for(i=0;i<n;i++){if(flag[a[i]]){last=i-1;if(last-begin>res_last-res_begin) {  res_begin=begin; res_last=last; }for(j=begin;j<=last;j++){if(a[i]==a[j]) break;flag[a[j]]=0;}begin=j+1;}elseflag[a[i]]=1;}if(n-1-begin>res_last-res_begin) {  res_begin=begin; res_last=n-1; }printf("%d %d %d\n",res_last-res_begin+1,res_begin,res_last);}return 0;}