hdu 7101 Time-division Multiplexing（滑动窗口）

Posted 2021-09-17 jpphy0

目录

• 问题
• 分析
• 代码

问题

hdu 7101 Time-division Multiplexing - https://acm.hdu.edu.cn/showproblem.php?pid=7101

分析

代码

#include<bits/stdc++.h>
using namespace std;
#define pos(x,y) st[x%y][x/y%len[x%y]]-'a'
typedef long long ll;
const int MXN = 105, MXM = 17;
int n, len[MXN], cnt[26];
char st[MXN][MXM];
int main(){
	int t, g, ml, f, f2;	
	scanf("%d", &t);
	while(t--){
		g = 1, ml = 0, f = f2 = 0;
		memset(cnt, 0, sizeof cnt);
		scanf("%d", &n);
		for(int i = 0; i < n; ++i){
			scanf("%s", st[i]);
			len[i] = strlen(st[i]);
			for(int j = 0; j < len[i]; ++j) f |= 1 << st[i][j] - 'a';
			if(len[i] > ml) ml = len[i];
			g = g*len[i]/__gcd(g, len[i]);
		}
		int p1 = 0, p2 = -1, tot = (g+ml)*n;
		int ans = tot;
		while(p2 < tot){
			while(f2 != f && p2 < tot){
				++p2;
				++cnt[pos(p2,n)];
				f2 |= 1 << pos(p2,n);
			}				
			while(f2 == f){
				ans = min(ans, p2-p1+1);
				--cnt[pos(p1,n)];
				if(cnt[pos(p1,n)] == 0) f2 &= ~(1 << pos(p1,n));
				++p1;
			}
		}
		printf("%d\\n", ans);
	}
    return 0;
}