4.20陕西2019ICPC省赛训练

E题
二分答案

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define IOS std::ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
#define endl "\n"

const int N=1e9+7;

string s;int n,k;


bool check(int l)
{
	int ans=0;
	for(int i=0;i<n;)
	{
		if(s[i]=='1') 
		{
			i+=l;
			ans++;
		}
		else
		i++;
	}
	if(ans>k)//不行 
	{
		return false;
	}
	else
	return true;
}


void solve()
{
	cin>>n>>k;
	cin>>s;
	int l=1;int r=n;
	while(l<r)
	{
		int mid=l+r>>1;
		if(check(mid)) r=mid;
		else
		l=mid+1;
	}
	cout<<l<<endl;
}

signed main()
{
	IOS
	int T=1;
	cin>>T;
	while(T--)
	{
		solve();
	}

    return 0;
}