We often go to supermarkets to buy some fruits or vegetables, and on the tag there prints the price for a kilo. But in some supermarkets, when asked how much the items are, the clerk will say that a yuan for b kilos (You don't need to care about what "yuan" is), the same as a / b yuan for a kilo.
Now imagine you'd like to buy m kilos of apples. You've asked n supermarkets and got the prices. Find the minimum cost for those apples.
You can assume that there are enough apples in all supermarkets.
InputThe first line contains two positive integers n and m (1 ≤ n ≤ 5 000, 1 ≤ m ≤ 100), denoting that there are n supermarkets and you want to buy m kilos of apples.
The following n lines describe the information of the supermarkets. Each line contains two positive integers a, b (1 ≤ a, b ≤ 100), denoting that in this supermarket, you are supposed to pay a yuan for b kilos of apples.
OutputThe only line, denoting the minimum cost for m kilos of apples. Please make sure that the absolute or relative error between your answer and the correct answer won't exceed 10 - 6.
Formally, let your answer be x, and the jury's answer be y. Your answer is considered correct if .
Examples input 3 5 1 2 3 4 1 3 output 1.66666667 input 2 1 99 100 98 99 output 0.98989899 NoteIn the first sample, you are supposed to buy 5 kilos of apples in supermarket 3. The cost is 5 / 3 yuan.
In the second sample, you are supposed to buy 1 kilo of apples in supermarket 2. The cost is 98 / 99 yuan.
找到单价最少的超市,然后单价*要买的数量
#include <iostream> #include <stdio.h> #include <string.h> using namespace std; int n,m; int a1,a2,b1,b2; int main() { scanf("%d%d",&n,&m); scanf("%d%d",&a1,&b1); for(int i=1;i<n;i++){ scanf("%d%d",&a2,&b2); if(a1*b2>a2*b1) a1 = a2, b1 = b2; } double ans = 1.0 * a1 * m / b1; printf("%.8lf\n",ans); return 0; }