Atcoder Beginner Contest 184A Determinant 题解

题目链接

输入 $a,b,c,d$，然后直接输出 $ad-bc$ 即可

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int a,b,c,d;
inline int read()
{
    
    
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){
    
    if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0' && ch<='9')s=(s<<3)+(s<<1)+(ch^48),ch=getchar();
	return s*w;
}
int main()
{
    
    
	a=read(),b=read(),c=read(),d=read();
	printf("%d\n",a*d-b*c);
	return 0;
}