POJ 3273 Monthly Expense (二分&最大化最小值)

Posted 2022-12-09 synapse7

http://poj.org/problem?id=3273

要特别注意l的初值选取，若这题输入的日开支可以是0的话，l应初始化为-1

/*63ms,556KB*/

#include<cstdio>
const int mx = 100005;

int n, mon, a[mx];

bool judge(int m)

	int sum = 0, cnt = 1;
	for (int i = 0; i < n; ++i)
	
		sum += a[i];
		if (sum > m)
		
			if (a[i] > m) return false;
			sum = a[i];
			++cnt;
		
		if (cnt > mon) return false;
	
	return true;


int main()

	scanf("%d%d", &n, &mon);
	int sum = 0;
	for (int i = 0; i < n; ++i) scanf("%d", &a[i]), sum += a[i];
	int l = 0, r = sum, m;
	while (l + 1 < r) judge(m = (l + r) >> 1) ? r = m : l = m;
	printf("%d", l + 1);
	return 0;