AcWing——3624. 三值字符串

双指针解法

#include<iostream>
#include<unordered_map>
using namespace std;
int main() {int n; cin >> n;while(n--){unordered_map<char, int> tree;string s; cin >> s;int ans = 0x7fffffff; for(int i = 0, j = 0; j < (int)s.size(); j++){tree[s[j]]++;while(tree[s[i]] > 1) tree[s[i++]]--;if(tree['1'] && tree['2'] && tree['3'])ans = min(ans, j-i+1);}if(ans == 0x7fffffff)  cout << 0 << '\n';else cout << ans << '\n';}return 0;
}