二分1.0

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
	int t;
	scanf("%d", &t);
	while(t--)
	{
		int n, m;//二分m 
		scanf("%d%d", &n, &m);
		int i, j, x, znum = 0;
		int flag[m+5];
		memset(flag, 0, sizeof(flag));
		for(i = 0; i < n; i++) 
		{
			scanf("%d", &x);
			if(x == 0) znum++;
			else flag[x] = 1;
		}
		int l = 1, r = m, mid;
		int sum, p;
		while(l+1<r)
		{
			mid = (l+r)/2;
			sum = 0;
			p = 0;
			for(i = 1; i <= mid; i++ )
			if(flag[i] == 0) sum++;
			if(sum<=znum) p = 1;
			else 
			{
				for(i = 2; i < m-mid; i++)
				{
					if(flag[i-1] == 0) sum--;
					if(flag[i+mid-1] == 0) sum++;
					if(sum<=znum) {p = 1; break;}
				}			
			}
			if(p) l = mid;
			else r = mid;
			//printf("%d %d\n", l, r);
		}
		p = 0;
		sum = 0;
		for(i = 1; i <= r; i++ ) if(flag[i] == 0) sum++;
			if(sum<=znum) p = 1;
			else 
			{
				for(i = 2; i < m-r; i++)
				{
					if(flag[i-1] == 0) sum--;
					if(flag[i+r-1] == 0) sum++;
					if(sum<=znum) {p = 1; break;}
				}			
			}
		if(p) printf("%d\n", r);
		else printf("%d\n", l);
	} 
	return 0;
}