题目[USACO21DEC.B]LonelyPhoto思路include<bits/stdc++.h>usingnamespacestd;defineintlonglongdefineN500010intn,m,i,j,k;intl[N],r[N],ans;chara[N];signedmain(){scanf("%d%s",&n,a+1);for(i=1,k=0;i<=n;++i)