Submission #743436

#	Time	Username	Problem	Language	Result	Execution time	Memory
743436		Dan4Life	Three Friends (BOI14_friends)	C++17	100 / 100	22 ms	10540 KiB

friends

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
 
#define pb push_back
#define mp make_pair
#define fir first
#define sec second
#define all(a) a.begin(), a.end()
 
const int maxn = 200010;
const ll MOD = 1e9+7;
const int INF = 1e9;
const ll LINF = 1e18;
ll n, m, a[maxn];
map<int, int> M, N;
string s, ss;
set<int> S, SS;
 
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n >> s;
    if(n%2==0){ cout << "NOT POSSIBLE"; return 0; }
    string x = s.substr(0, n/2), y = s.substr(n/2+1, n/2);
    if(x==y){ cout << x; return 0; }
    string X = "", Y = "";
    int i = n/2, z= 0;
    for(i; i<n; i++) if(z<x.size() and x[z]==s[i])X+=s[i], z++;
    i=z=0;
    for(i; i <= n/2; i++) if(z<y.size() and y[z]==s[i])Y+=s[i],z++;
    if(X==x and Y==y) cout << "NOT UNIQUE";
    else if(X==x or Y==y)  cout << (X==x?x:y);
    else cout << "NOT POSSIBLE";
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:30:9: warning: statement has no effect [-Wunused-value]
   30 |     for(i; i<n; i++) if(z<x.size() and x[z]==s[i])X+=s[i], z++;
      |         ^
friends.cpp:30:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for(i; i<n; i++) if(z<x.size() and x[z]==s[i])X+=s[i], z++;
      |                         ~^~~~~~~~~
friends.cpp:32:9: warning: statement has no effect [-Wunused-value]
   32 |     for(i; i <= n/2; i++) if(z<y.size() and y[z]==s[i])Y+=s[i],z++;
      |         ^
friends.cpp:32:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for(i; i <= n/2; i++) if(z<y.size() and y[z]==s[i])Y+=s[i],z++;
      |                              ~^~~~~~~~~

• Subtask 1: 35 / 35
• Subtask 2: 65 / 65