724A - Checking the Calendar - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
map <string,int> m;
int main(){
m["monday"]=1;
m["tuesday"]=2;
m["wednesday"]=3;
m["thursday"]=4;
m["friday"]=5;
m["saturday"]=6;
m["sunday"]=7;
string a,b;
cin>>a>>b;//读入
int x=m[a],y=m[b];
if((y+7-x)%7==0||(y+7-x)%7==2||(y+7-x)%7==3) cout<<"YES";
else cout<<"NO";
cout<<endl;
return 0;
}