Submission #217603

#	Time	Username	Problem	Language	Result	Execution time	Memory
217603		KoalaMuch	Three Friends (BOI14_friends)	C++14	0 / 100	68 ms	7404 KiB

friends

#include<bits/stdc++.h>
using namespace std;
const int N = 2000005;
char s[N];
vector< char > ans1;
vector< char > ans2;
void pr(vector< char > v)
{
    for(char x : v) printf("%c",x);
    printf("\n");
}
int main()
{
    int n;
    scanf("%d %s",&n,s+1);
    if(!(n&1)) return puts("NOT POSSIBLE"),0;
    int cur = n/2+1;
    bool ch = false;
    for(int i=1;i<=n/2;i++)
    {
        while(s[i]!=s[cur]&&cur<=n)    ++cur;
        if(s[i]!=s[cur]|cur==n+1)    {ch = true;break;}
    }
    if(!ch) for(int i=1;i<=n/2;i++) ans1.push_back(s[i]);
    cur = 1,ch = false;
    for(int i=(n+1)/2+1;i<=n;i++)
    {
        while(s[i]!=s[cur]&&cur<=(n+1)/2)    ++cur;
        if(s[i]!=s[cur]||cur==(n+1)/2+1)    {ch=true;break;}
    }
    if(!ch) for(int i=(n+1)/2+1;i<=n;i++) ans2.push_back(s[i]);
    if(ans1.empty()&&ans2.empty())       printf("NOT POSSIBLE\n");
    else if(!ans1.empty()&&ans2.empty()) pr(ans1);
    else if(!ans2.empty()&&ans1.empty()) pr(ans2);
    else if(!ans1.empty()&&ans1!=ans2)   printf("NOT UNIQUE\n");
    else                                 pr(ans1);
    return 0;
}
/*
7
ABXCABC

6
ABCDEF
*/

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:22:16: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
         if(s[i]!=s[cur]|cur==n+1)    {ch = true;break;}
            ~~~~^~~~~~~~
friends.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %s",&n,s+1);
     ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 0 / 35
• Subtask 2: 0 / 65