codeforce 621B Wet Shark and Bishops

对角线 x1+y1=x2+y2 或者x1-y1=x2-y2

 #include<iostream>
 #include<string>
 #include<algorithm>
 #include<cstdlib>
 #include<cstdio>
 #include<set>
 #include<map>
 #include<vector>
 #include<cstring>
 #include<stack>
 #include<cmath>
 #include<queue>
 #include <bits/stdc++.h>
 using namespace std;
 #define INF 0x3f3f3f3f
 #define ll long long
 #define clc(a,b) memset(a,b,sizeof(a))
 const int maxn=;

 int main()
 {
     int n;
     int x,y;
     int a[maxn];
     int b[maxn];
     scanf("%d",&n);
     clc(a,);
     clc(b,);
     for(int i=;i<n;i++)
     {
         scanf("%d%d",&x,&y);
         a[x+y]++;
         b[x-y+]++;
     }
     ll sum=;
     for(int i=;i<=;i++)
     {
         if(a[i]%)
             sum+=(a[i]-)/*a[i];
         else
             sum+=a[i]/*(a[i]-);
     }
     for(int i=-+;i<=+;i++)
     {
         if(b[i]%)
             sum+=(b[i]-)/*b[i];
         else
             sum+=b[i]/*(b[i]-);
     }
     printf("%I64d\n",sum);
     return ;
 }