rt

code:

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a,b,q,min_,max_;
	cin>>a>>b>>q;
	min_=min(a,b),max_=max(a,b);
	while(q--)
	{
		int l,r;
		cin>>l>>r;
		if(l<min_) cout/*<<" 1=>"*/<<(min_-1)%a+(min_-1)%b;
		else if(l==min_) 
		{
			if(r>=max_) cout/*<<" 2=>"*/<<(max_-1)%a+(max_-1)%b;
			else cout/*<<" 3=>"*/<<r%a+r%b;
		}
		else
		{
			if(r<(l/min_+1)*min_) cout/*<<" 4=>"*/<<r%a+r%b;
			else cout/*<<" 5=>"*/<<((l/min_+1)*min_-1)%a+((l/min_+1)*min_-1)%b;
		}
		cout<<'\n';
	}
}

思路：推式子