nowcoder 天气预报

https://ac.nowcoder.com/acm/problem/235096

 

双指针，就按这个形式写了

 

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#include <iostream> #include <map> #include <cstring> #include <algorithm> using namespace std ;  const int  N=1e6+10;  #define int long long     int n,a,b;  int A ;  char s[N];     signed main(){     int l,r;     cin>>n>>a>>b;     cin>>(s+1);    n=strlen(s+1) ;     int c1=0,c2=0,ans=0 ;     l=1,r=1;           while(r<=n){         if(s[r]=='0') c1++; else c2++;                   while(l<=r &&(c1>=a) && (c2>=b)){             ans+= n-r+1;             if(s[l]=='0') c1--; else c2--;             l++;         }         r++;     }     if(a+b==0) ans++;     cout<<ans<<endl;  }