Submission #1294599

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Source Code Expand

#define _USE_MATH_DEFINES
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>

using namespace std;

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

typedef long long int64;
typedef pair<int, int> ii;
const int INF = 1 << 30;
const int MOD = 1e9 + 7;

const int N = 1e5 + 10;
vector<int> a[N];
int dp[N], ret[N];

void DFS(int u, int parent) {
  int sum = 0, common = 0;
  for (auto& v : a[u]) {
    if (v == parent) continue;
    DFS(v, u);
    common |= dp[v] & sum;
    sum |= dp[v];
  }
  int k;
  for (k = 0; (sum & (1 << k)) || (1 << k) <= common; ++k);
  ret[u] = k;
  dp[u] = ((sum >> k) | 1) << k;
}

int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i < n; ++i) {
    int x, y;
    scanf("%d%d", &x, &y);
    --x; --y;
    a[x].push_back(y);
    a[y].push_back(x);
  }
  DFS(0, -1);
  int ans = *max_element(ret, ret + n);
  printf("%d\n", ans);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:61:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^
./Main.cpp:64:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &x, &y);
                          ^

Judge Result