Submission #2162126

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Source Code Expand

#include <stdio.h>
#include <bits/stdc++.h>			

#define pb push_back
#define pf push_front
#define pp pop_back
#define sz(a) (int)(a.size())
#define mp make_pair
#define F first
#define S second
#define next _next
#define prev _prev
#define left _left
#define right _right
#define y1 _y1
#define all(x) x.begin(), x.end()
#define what_is(x) #x << " is " << (x)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int N = (int)1e6 + 123;
const ll INF = (ll)1e18 + 123;
const int inf = (int)1e9 + 123;
const int MOD = (int)1e9 + 7;

void megaRandom() {
	unsigned int FOR;
 	asm("rdtsc" : "=A"(FOR));
  srand(FOR);
}

int n, a[N];
bool u[N];
vector<int> g[N];

int rec(int x) {
	u[x] = 1;
	set<pii> st;
	for(auto to : g[x]) {
	  if(u[to]) continue;
		st.insert(mp(rec(to), to));
	}
	int mx = 0, height = sz(st);//sz(g[x]) - 1;
	while(sz(st) > 0) {
		pii now = *st.begin();
		st.erase(st.begin());
		mx = max(mx, height + now.F);		
		height --;
	}
	return mx;
}

int main() {
	megaRandom();
	scanf("%d", &n);
	for(int i = 2; i <= n; i ++) {
		scanf("%d", &a[i]);
		g[i].pb(a[i]);
		g[a[i]].pb(i);
	}
	printf("%d", rec(1));
	return 0;  
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:61:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
./Main.cpp:63:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
                     ^

Judge Result