Submission #36416874

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Source Code Expand

#include <bits/stdc++.h>
#define st first
#define nd second
#define db double
#define re register
#define pb push_back
#define mk make_pair
#define int long long
#define ldb long double
#define pii pair<int, int>
#define ull unsigned long long
#define mst(a, b) memset(a, b, sizeof(a))
using namespace std;
const int N = 4e5 + 10, INF = 1e16;
inline int read()
{
  int s = 0, w = 1;
  char ch = getchar();
  while(ch < '0' || ch > '9') { if(ch == '-') w *= -1; ch = getchar(); }
  while(ch >= '0' && ch <= '9') s = s * 10 + ch - '0', ch = getchar();
  return s * w;
}
int n, t;
int a[N], b[N], c[N];
bool vis[N];
vector<int> G[N];
inline void DFS(int u)
{
  vis[u] = true;
  for(re int to : G[u]) if(!vis[to]) DFS(to);
}
signed main()
{
  n = read(), c[++t] = 1;
  for(re int i = 1; i <= n; i++)
    a[i] = read(), b[i] = read(), c[++t] = a[i], c[++t] = b[i];
  sort(c + 1, c + t + 1), t = unique(c + 1, c + t + 1) - c - 1;
  for(re int i = 1; i <= n; i++){
    a[i] = lower_bound(c + 1, c + t + 1, a[i]) - c;
    b[i] = lower_bound(c + 1, c + t + 1, b[i]) - c;
    G[a[i]].pb(b[i]), G[b[i]].pb(a[i]);
  }
  DFS(1);
  for(re int i = t; i >= 1; i--)
    if(vis[i]) printf("%lld\n", c[i]), exit(0);
  return 0;
}
/*
1
10
9 9 4 7 3 10 10 8 4 3
*/

Submission Info

Compile Error

./Main.cpp: In function ‘void DFS(long long int)’:
./Main.cpp:30:14: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   30 |   for(re int to : G[u]) if(!vis[to]) DFS(to);
      |              ^~
./Main.cpp: In function ‘int main()’:
./Main.cpp:35:14: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   35 |   for(re int i = 1; i <= n; i++)
      |              ^
./Main.cpp:38:14: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   38 |   for(re int i = 1; i <= n; i++){
      |              ^
./Main.cpp:44:14: warning: ISO C++17 does not allow ‘register’ storage class specifier [-Wregister]
   44 |   for(re int i = t; i >= 1; i--)
      |              ^

Judge Result