#include <stdio.h>#include <stdlib.h>#include <algorithm>#include <iostream>using namespace std;struct rect { int left, right, top, bottom; int rank_x;} rec[32];int T, K, P;int cmp_x(const void *a, const void *b){ return ((struct rect *)a)->left - ((struct rect *)b)->left;}int cmp_y(const void *a, const void *b){ return ((struct rect *)a)->top - ((struct rect *)b)->top;}inline int solve(){ int i, last, rank, mask; qsort(rec, K, sizeof(rec[0]), cmp_x); rank = 0; for (i = 0; i < K; ) { last = rec[i].right; while (i < K && rec[i].left <= last) { rec[i].rank_x = rank; last = max(last, rec[i].right); i++; } rank++; } qsort(rec, K, sizeof(rec[0]), cmp_y); for (i = 0; i < K; ) { mask = 0; last = rec[i].bottom; while (i < K && rec[i].top <= last) { if (mask & (1 << rec[i].rank_x)) return 0; mask |= 1 << rec[i].rank_x; last = max(last, rec[i].bottom); i++; } } return 1;}int main(){ int i, j, x, y; scanf("%d", &T); while (T--) { scanf("%d%d", &K, &P); for (i = 0; i < K; i++) { rec[i].left = rec[i].top = 1000000; rec[i].right = rec[i].bottom = 0; for (j = 0; j < P; j++) { scanf("%d%d", &x, &y); if (x < rec[i].left) rec[i].left = x; if (x > rec[i].right) rec[i].right = x; if (y < rec[i].top) rec[i].top = y; if (y > rec[i].bottom) rec[i].bottom = y; } } printf("%sn", solve() ? "YES" : "NO"); } return 0;}
