Fabled Rooks UVA - 11134 _∑bit

很不错的题，利用贪心解决

代码参考别人的

#include<iostream>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iomanip>
#include<assert.h>
#include<vector>
#include<list>
#include<map>
#include<sstream>
#include<stack>
#include<queue>
#include<string>
#include<bitset>
#include<algorithm>
#pragma warning(disable:4996)
#define _for(i,a,b) for(int i=(a);i<(b);++i)
#define _rep(i,a,b) for(int i=(a);i<=(b)++i)
#define Max(a,b) (a)>(b)?(a):(b);
#define Min(a,b) (a)<(b)?(a):(b);
using namespace std;
typedef long long ll;
typedef unsigned long long llu;
const int INT_INF = 0x3f3f3f3f;
const int INT_M_INF = 0x7f7f7f7f;
const ll LL_INF = 0x3f3f3f3f3f3f3f3f;
const ll LL_M_INF = 0x7f7f7f7f7f7f7f7f;
const int dr[] = { 0, -1, 0, 1, -1, -1, 1, 1 };
const int dc[] = { -1, 0, 1, 0, -1, 1, -1, 1 };
const int MOD = 1e9 + 7;
const double pi = acos(-1.0);
const double eps = 1e-15;
const int N = 5000 + 10;
int xx[N], yy[N], x2[N], y2[N], x[N], y[N], n;
bool solve(int* A, int* B,int *C,int n)
{
	fill(C, C + n, -1);
	for (int col = 1; col <= n; col++) {
		int rock = -1; int maxb = n + 1;
		for (int i = 0; i < n; i++) {
			if (C[i] < 0 && B[i] < maxb&&A[i] <= col) { //右边留空间越大越好
				maxb = B[i]; rock = i;
			}
		}
		if (rock<0 || col>maxb) return false;//如果没有找到，或者虽然找到了，但是最大范围小于col,则无解
		C[rock] = col;
	}
	return true;
}
int main()
{
	while (scanf("%d", &n) == 1) {
		_for(i, 0, n)
			scanf("%d%d%d%d", &xx[i], &yy[i], &x2[i], &y2[i]);
		if (solve(xx, x2, x, n) && solve(yy, y2, y, n))
			_for(i, 0, n) printf("%d %d\n", x[i], y[i]);
		else printf("IMPOSSIBLE\n");	
	}
}
#include<iostream>
#in