Submission #1074404

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long long LL;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef vector<int> vi;

#ifdef DEBUG
    #define cek(x) cout<<x
#else
    #define cek(x) if(false){}
#endif // DEBUG

#define fi first
#define se second
#define INF 1000000000
#define INFLL 1000000000000000000LL
#define EPS 1e-9
#define PI acos(-1.0)
#define pb push_back
#define TC() while(tc--)
#define FOR(i,n) for(int i=0;i<n;i++)
#define FORN(i,n) for(int i=0;i<=n;i++)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define REPN(i,a,b) for(int i=a;i<=b;i++)
#define reset(a,b) memset(a,b,sizeof(a))
#define sc(x) scanf("%d",&x)

void open(){
	freopen("D:/Code/in.txt","r",stdin);
	freopen("D:/Code/out.txt", "w", stdout);
}

int inc[100010];
vi adjList[100010];
int lvl[100010];

int main(void){
	int n;
	sc(n);
	reset(lvl, 0);
	for(int i = 1;i<n;i++){
		int x;
		sc(x);
		x--;
		adjList[i].pb(x);
		inc[x]++;
	}
	queue<int> q;
	for(int i = 0;i<n;i++){
		if(!inc[i])q.push(i);
	}
	while(!q.empty()){
		int cur = q.front();q.pop();
		for(int i = 0;i<adjList[cur].size();i++){
			int nxt = adjList[cur][i];
			inc[nxt]--;
			lvl[nxt] = max(lvl[nxt] + 1, lvl[cur] + 1);
			if(inc[nxt] == 0){
				q.push(nxt);
				
			}
		}
	}
	cout << lvl[0] << endl;
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘void open()’:
./Main.cpp:32:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen("D:/Code/in.txt","r",stdin);
                                     ^
./Main.cpp:33:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen("D:/Code/out.txt", "w", stdout);
                                         ^
./Main.cpp: In function ‘int main()’:
./Main.cpp:42:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  sc(n);
       ^
./Main.cpp:46:8: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   sc(x);
        ^

Judge Result