仿照之前的雪花，Hash函数随便搞个。
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#include <cstdio>#include <cstdlib>#include <cstring>#include <algorithm>#include <cmath>#include <stack>#include <queue>#include <vector>#include <map>#include <string>#include <iostream>const
int INF = 9973;const
int kk = 1007;struct
Node{ int
x;int y; int
hash_val;}node[INF][100];int
Abs(int
x){ return
x>0?x:-x;}int
get_hash(Node &a){ a.hash_val= a.x*a.y+a.y*kk; return
a.hash_val = Abs(a.hash_val)%INF;}int
Hash(int
x,int y){ return
Abs(x*y+y*kk)%INF;}int
len[INF];void
Insert(Node a){ int
val=get_hash(a); for(int
i=0;i<len[a.hash_val];i++) if(node[val][i].x==a.x&&node[val][i].y==a.y) return
; node[val][len[a.hash_val]++]=a;}int
match(int
x,int y){ int
hash1=Hash(x,y); for(int
i=0;i<len[hash1];i++) if(node[hash1][i].x==x&&node[hash1][i].y==y) return
1; return
0;}int
main(){ int
n; Node a[20000]; while(scanf("%d",&n),n){ memset(node,0,sizeof(node)); memset(len,0,sizeof(len)); for(int
i=0;i<n;i++){ scanf("%d%d",&a[i].x,&a[i].y); int
val=get_hash(a[i]); Insert(a[i]); } int
ans=0; for(int
i=0;i<n;i++){ for(int
j=i+1;j<n;j++){ int
x1=a[i].x-a[i].y+a[j].y;int
y1=a[i].y-a[j].x+a[i].x; int
x2=a[j].x+a[j].y-a[i].y;int
y2=a[j].y-a[j].x+a[i].x; int
x3=a[i].x-a[j].y+a[i].y;int
y3=a[i].y-a[i].x+a[j].x; int
x4=a[j].x-a[j].y+a[i].y;int
y4=a[j].y+a[j].x-a[i].x; if(match(x1,y1)&&match(x2,y2)) ans++; if(match(x3,y3)&&match(x4,y4)) ans++; } } printf("%d\n",ans/4); } return
0;} |
Hash poj2002 Squares,布布扣,bubuko.com
原文地址：http://www.cnblogs.com/yigexigua/p/3761340.html
