第二题 我的程序为什么能过啊？

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N = 2e5;
int n;
int nw[N + 5];
int ans[N + 5];
struct node {
	int k;
	int a,b,c;
}v[N + 5];
bool cmp1(node x,node y) {
	return x.a > y.a;
}
bool cmp2(node x,node y) {
	return x.b > y.b;
}
bool cmp3(node x,node y) {
	return x.c > y.c;
}
signed main() {
	cin >> n;
	memset(ans,0x3f3f3f,sizeof(ans));
	for(int i = 1 ; i <= n ; i ++) {
		cin >> v[i].a >> v[i].b >> v[i].c;
		v[i].k = i;
	}
	sort(v + 1,v + n + 1,cmp1);
	for(int i = 1 ; i <= n ; i ++) {
		int p = v[i].k;
		if(v[i].a == v[i - 1].a) {
			nw[p] = nw[v[i - 1].k];
		} else nw[p] = i;
		ans[p] = min(ans[p],nw[p]);
	}
	sort(v + 1,v + n + 1,cmp2);
	for(int i = 1 ; i <= n ; i ++) {
		int p = v[i].k;
		if(v[i].b == v[i - 1].b) {
			nw[p] = nw[v[i - 1].k];
		} else nw[p] = i;
		ans[p] = min(ans[p],nw[p]);
	}
	sort(v + 1,v + n + 1,cmp3);
	for(int i = 1 ; i <= n ; i ++) {
		int p = v[i].k;
		if(v[i].c == v[i - 1].c) {
			nw[p] = nw[v[i - 1].k];
		} else nw[p] = i;
		ans[p] = min(ans[p],nw[p]);
	}
	for(int i = 1 ; i <= n ; i ++)
		cout << ans[i] << endl;
	return 0;
}

难道我时间复杂度算错了？