A. Road To Zero1000 / 贪心

Posted 2021-10-04 幽殇默

https://codeforces.com/problemset/problem/1342/A

#include<bits/stdc++.h>
using namespace std;
typedef long long int LL;
int main(void)
{
	LL t; cin>>t;
	while(t--)
	{
		LL x,y,a,b; cin>>x>>y>>a>>b;
		LL sum=0;
		if(2*a>=b) sum=min(x,y)*b+labs(x-y)*a; 
		else sum=(x+y)*a;
		cout<<sum<<endl;
	}
	return 0;
}