HDU 5056 boring count (Mathematics)

Question link: http://acm.hdu.edu.cn/showproblem.php? PID = 1, 5056

Problem descriptionyou are given a string s consisting of lowercase letters, and your task is counting the number of substring that the number of each lowercase letter in the substring is no more than K. inputin the first line there is an integer T, indicates the number of test cases.
For each case, the first line contains a string which only consist of lowercase letters. The second line contains an integer k.

[Technical Specification]
1 <= T <= 100
1 <= length of S <= 100000
1 <= k <= 100000 outputfor each case, output a line contains the answer. sample input

3abc1abcabc1abcabc2

Sample output

61521

Sourcebestcoder round #11 (Div. 2)

Official question:

The Code is as follows:

#include <cstdio>#include <cstring>const int maxn = 100017;int main(){    int t;    char str[maxn];    int st[27];    int k;    scanf("%d",&t);    while(t--)    {        memset(st,0,sizeof(st));        scanf("%s",str);        scanf("%d",&k);        __int64 ans = 0;        int len = strlen(str);        int startpos = 0;        for(int i = 0; i < len; i++)        {            int tt = str[i] -'a';            st[tt]++;            if(st[tt] > k)            {                while(str[startpos]!=str[i])                {                    st[str[startpos]-'a']--;                    startpos++;                }                st[str[startpos]-'a']--;                startpos++;            }            ans+=i-startpos+1;        }        printf("%I64d\n",ans);    }    return 0;}

HDU 5056 boring count (Mathematics)