HDU 5672：String【模拟】

String

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 892    Accepted Submission(s): 289

Problem Description

There is a string S.S only contain lower case English character.(10≤length(S)≤1,000,000)
How many substrings there are that contain at least k(1≤k≤26) distinct characters?

 

Input

There are multiple test cases. The first line of input contains an integer T(1≤T≤10) indicating the number of test cases. For each test case:

The first line contains string S.
The second line contains a integer k(1≤k≤26).

 

Output

For each test case, output the number of substrings that contain at least k dictinct characters.

 

Sample Input

2abcabcabca4abcabcabcabc3

 

Sample Output

055
醉了，G++超时，C++过了。。。。
AC-code：
#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;int main(){int T,k,len,i,j,kk,vis[27];long long sum;char str[1000005];scanf("%d",&T);while(T--){cin>>str;cin>>k;len=strlen(str);if(k==1){cout<<(long long)(len+1)*len/2<<endl;continue;}kk=0;sum=0;memset(vis,0,sizeof(vis));j=0;for(i=0;i<len;i++){if(!vis[str[i]-'a'])kk++;vis[str[i]-'a']++;while(kk>=k){sum+=len-i;vis[str[j]-'a']--;if(!vis[str[j]-'a']){kk--;j++;break;}j++;}}cout<<sum<<endl;}return 0; }