太正经题解|kingdom Game I

一道小小的二分，check函数也不是很难写，代码：

#include <iostream>
#include <algorithm>
using namespace std;
const int N=2e5+5;
int w[N],v[N];
int A(int n,long long m,long long x) {
	long long sum=0;
	for (int i=1;i<=n;i++) {
		if (x<w[i]) {
			sum-=v[i];
		}else {
			sum+=(x/w[i])*v[i];
		}
	}
	if (sum>=m) return 1;
	return 0;
}
int main() {
	int n;
	long long m,l=1e18,r=4e4,ans=2e18;
	scanf("%d %lld",&n,&m);
	for (int i=1;i<=n;i++) {
		scanf("%d",&w[i]);
		l=min(l,(long long)w[i]);
	}
	for (int i=1;i<=n;i++) {
		scanf("%d",&v[i]);
	}
	while (l<=r) {
		long long mid=(l+r)>>1;
		if (A(n,m,mid)==1) {
			ans=min(ans,mid);
			r=mid-1;
		}else {
			l=mid+1;
		}
	}
	printf("%lld",ans);
	return 0;
}