尺取法 枚举区间

3
5 3
ccbaa
11 3
abbbbdbbbbc
4 3
abba

3
11
I am so fat!



#include <cstdio>
#include <iostream>
#include <algorithm>
#include <queue>
#include <stack>
#include <climits>
#include <cstring>
#include <cmath>
#include <map>
#include <set>
#define INF 100000000

using namespace std;

int n,m;
char a[1005];
int num[30];


int main(){
	int t;
	cin >> t;
	while(t--){
		cin >> n >> m;
		scanf("%s",a);
		
		int s = 0;
		int e = 0;
		memset(num,0,sizeof(num));
		int cc = 0;
		
		
		int ans = INF;
		
		while(s < n){
			while(cc < m && e < n){
				if(a[e]-'a' < m && num[a[e]-'a'] == 0) 
					cc++;
				num[a[e] - 'a'] ++;
				e++; 
			}
			if((e-s) < ans && cc >= m) ans = e-s;
			num[a[s]-'a']--;
			if(a[s]-'a' < m && num[a[s]-'a'] == 0){
				cc--;
			}
			s++;
			if((e-s) < ans && cc >= m) ans = e-s;
			
		}
		if(ans == INF)
			cout << "I am so fat!"<< endl;
		else
			cout << ans << endl;
	}	
	return 0;
}