E - Class

开局一条鲲_ · 2021-04-12 21:50:33 · 个人记录

Avin has two integers a, b (1 ≤ a, b ≤ 1, 000). Given x = a + b and y = a - b, can you calculate a*b?

Input

The first line contains two integers x, y.

Output

Print the result of a*b.

Sample Input

4 2

Sample Output

3

题解：(x+y)/2=a , (x-y)/2=b.

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;

int a,b,x,y,s;

int main()
{
    scanf("%d%d",&a,&b);
    x=(a+b)/2;
    y=(a-b)/2;
    s=x*y;
    printf("%d\n",s);
    return 0;
}