Submission #4864

#	Time	Username	Problem	Language	Result	Execution time	Memory
4864		tncks0121	Star triangles (IZhO11_triangle)	C++98	100 / 100	216 ms	8120 KiB

triangle

#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <memory.h> 
#include <math.h> 
#include <assert.h> 
#include <stack> 
#include <queue> 
#include <map> 
#include <set> 
#include <algorithm> 
#include <string> 
#include <functional> 
#include <vector> 
#include <deque> 
#include <utility> 
#include <bitset> 
#include <limits.h>  
#include <time.h>

using namespace std; 
typedef long long ll; 
typedef unsigned long long llu; 
typedef double lf;
typedef unsigned int uint;
typedef long double llf;
typedef pair<int, int> pii;

const int N_ = 300005;

int N, X[N_], Y[N_];

int *P[N_];
bool cmpP (const int *a, const int *b) { return *a < *b; }

int CX[N_], CY[N_];
ll res;

int main() {
	int i, j, k;
	
	scanf("%d", &N);
	for(i = 1; i <= N; i++) scanf("%d%d", X+i, Y+i);

	for(i = 1; i <= N; i++) P[i] = &X[i];
	sort(P+1, P+N+1, cmpP);

	for(k = -1, j = 0, i = 1; i <= N; i++) {
		if(k != *P[i]) k = *P[i], ++j;
		*P[i] = j;
	}

	for(i = 1; i <= N; i++) P[i] = &Y[i];
	sort(P+1, P+N+1, cmpP);

	for(k = -1, j = 0, i = 1; i <= N; i++) {
		if(k != *P[i]) k = *P[i], ++j;
		*P[i] = j;
	}

	for(i = 1; i <= N; i++) ++CX[X[i]], ++CY[Y[i]];

	for(i = 1; i <= N; i++) {
		res += (ll) (CX[X[i]] - 1) * (CY[Y[i]] - 1);
	}

	printf("%lld\n", res);
	return 0;
}

• Subtask 1: 100 / 100