这题刚开始卡住了,没有理解每组第二个b是什么,以为是ab,2ab,3ab,4ab,…,nab,所以卡住了实际上是边界n,即到ab终止
#include<iostream>
#include<algorithm>
using namespace std;
double a;
int b;
int lamp[2000005];
int main()
{
int n;
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> a >> b;
for (int j = 1; j<=b; j++)
{
if (lamp[int(a * j)] == 1)lamp[int(a * j)] = 0;
else
lamp[int(a * j)] = 1;
}
}
for (int i = 1;; i++)
{
if (lamp[i] == 1)
{
cout << i;
break;
}
}
}