pku acm 1064

二分搜索的應用

#include <iostream>
#include <cstdio>
#include <iomanip>
using namespace std;

int intCables[10002];//單位cm

bool numberCuts(int index,int k,int length)//cm單位
{
	long long lnums = 0;
	for (int i = 0; i < index; ++i)
	{
		lnums += intCables[i]/length;
		if (lnums >= k)return true;
	}

	return false;
}

int main()
{
	freopen("in.txt","r",stdin);

	int N,K;// 1 <= N, K <= 10000
	int index = 0;
	float fCable;
	cin>>N>>K;
	while (N--)
	{
		cin>>fCable;//單位是m
		intCables[index++] = (int)(1000*fCable+5)/10;//轉換成cm存儲
	}

	int left = 1,right = 10000000;
	int mid, ans = 0;
	while (left <= right)
	{
		mid = (left + right)/2;
		if (numberCuts(index,K,mid))
		{
			ans = mid; //這裏很關鍵
			left = mid + 1;
		}
		else
			right = mid - 1;	
	}

	if (ans < 1)
		cout<<"0.00"<<endl;
	else
		cout<<fixed<<setprecision(2)<<(ans*1.0/100)<<endl;	
}

題目看錯了，小於1 cm才輸出0.00，我卻看成是小於1m，TMD! 提交了N次不通過