题目链接 题意：求曼哈顿距离和平方根距离相等的点的对数？ 思路：化简发现是绝对值乘积等于0，容斥搞搞。
代码实现
1/* ***********************************************
2Author :111qqz
3Created Time :2016年03月07日 星期一 18时43分02秒
4File Name :code/C.cpp
5************************************************ */
6
7#include <cstdio>
8#include <cstring>
9#include <iostream>
10#include <algorithm>
11#include <vector>
12#include <queue>
13#include <set>
14#include <map>
15#include <string>
16#include <cmath>
17#include <cstdlib>
18#include <ctime>
19#define fst first
20#define sec second
21#define lson l,m,rt<<1
22#define rson m+1,r,rt<<1|1
23#define ms(a,x) memset(a,x,sizeof(a))
24typedef long long LL;
25#define pi pair < int ,int >
26#define MP make_pair
27
28using namespace std;
29const double eps = 1E-8;
30const int dx4[4]={1,0,0,-1};
31const int dy4[4]={0,-1,1,0};
32const int inf = 0x3f3f3f3f;
33const int N=2E6+7;
34
35struct node
36{
37 int x,y;
38
39 bool operator < (node b)const
40 {
41 if (x==b.x) return y<b.y;
42 return x<b.x;
43 }
44}p[N];
45
46
47
48bool cmp( node a,node b)
49{
50 return a.y<b.y;
51}
52LL cal( LL x)
53{
54 LL res = x*(x+1)/2;
55 return res;
56}
57int n;
58LL a,b,c;
59LL cnta,cntb,cntc;
60int main()
61{
62 #ifndef ONLINE_JUDGE
63 freopen("code/in.txt","r",stdin);
64 #endif
65
66 ios::sync_with_stdio(false);
67 cin>>n;
68 for ( int i = 1 ;i <= n ; i++) cin>>p[i].x>>p[i].y;
69
70 sort(p+1,p+n+1);
71
72 a=b=c=0LL;
73 cnta=cntb=cntc=0LL;
74
75
76 for ( int i = 1 ; i <= n-1 ; i++)
77 {
78 if (p[i].x==p[i+1].x)
79 {
80 cnta++;
81 }
82 else
83 {
84 a+=cal(cnta);
85 cnta = 0 ;
86 }
87 }
88 a +=cal(cnta);
89
90
91 for ( int i = 1 ; i <= n-1 ; i++)
92 {
93 if (p[i].x==p[i+1].x&&p[i].y==p[i+1].y)
94 {
95 cntc++;
96 }
97 else
98 {
99 c +=cal(cntc);
100 cntc = 0 ;
101 }
102 }
103
104 c+=cal(cntc);
105
106
107
108 sort(p+1,p+n+1,cmp);
109 for ( int i = 1 ; i <= n-1 ; i ++)
110 {
111 if (p[i].y==p[i+1].y)
112 {
113 cntb++;
114 }
115 else
116 {
117 b +=cal(cntb);
118 cntb = 0 ;
119 }
120 }
121 b +=cal(cntb);
122
123 LL ans=0LL;
124 ans = a+b-c;
125 cout<<ans<<endl;
126
127 #ifndef ONLINE_JUDGE
128 fclose(stdin);
129 #endif
130 return 0;
131}