POJ 2481 Cows

It's a tree_array problem.

The portal:http://poj.org/problem?id=2481

#include <cstdio>#include <cstdlib>#include <cstring>#include <cmath>#include <iostream>using namespace std;const int N = 1e5+5;const int M = 1e5+5;int Bit[M << 1];struct Node {int x,y,r,value;}a[N];void Insert(int x,int value) {for(int i = x; i <= M; i += i & (-i)){Bit[i] += value;}}int Query(int x){int ret = 0;if(x <= 0)return 0;for(int i = x;i;i -= i & (-i)){ret += Bit[i];}return ret;}int cmp1(const void * a1,const void * a2){struct Node p1 = *(struct Node *)a1;struct Node p2 = *(struct Node *)a2;if(p1.y == p2.y) return p1.x - p2.x;return p2.y - p1.y;}int cmp2(const void * a1,const void * a2){struct Node p1 = *(struct Node *)a1;struct Node p2 = *(struct Node *)a2;return p1.r - p2.r;}void Deal_with(){int n;while(scanf("%d",&n),n){memset(a,0,sizeof(a));memset(Bit,0,sizeof(Bit));for(int i=0;i<n;i++){scanf("%d %d",&a[i].x,&a[i].y);a[i].x ++ ; a[i].y ++;//Because a[i].x may equal '0';a[i].r = i;}qsort(a,n,sizeof(struct Node),cmp1);//Use y to first condition.(From higher to lower);Use x to second condition.(From lower to higher.) Insert(a[0].x,1);for(int i=1;i<n;i++){if(a[i].x == a[i-1].x && a[i].y == a[i-1].y){a[i].value = a[i-1].value;Insert(a[i].x,1);//Add the line is important; continue;}a[i].value = Query(a[i].x);Insert(a[i].x,1);}qsort(a,n,sizeof(struct Node),cmp2);//Use a[i].r to recmp the array a;for(int i=0;i<n;i++){printf("%d",a[i].value);printf(i == n - 1 ? "\n" : " ");// if (i == n - 1) printf("\n"); else printf(" ");}}}int main(void){//freopen("a.in","r",stdin);Deal_with();return 0;}