Language: C++

#include<iostream>                                                                                                      using namespace std;                                                                                                    #define rep(i,n) for(int i=0;i<n;i++)                                                                                   #include<vector>                                                                                                                                                                                                                                                                                                                                                        int main(){                                                                                                                     int n,m;                                                                                                                cin >> n >> m;                                                                                                                                                                                                                                  int c[n],s,ct;                                                                                                          rep(i,n)c[i]=0;                                                                                                         rep(i,m){                                                                                                                       cin >> s >> ct;                                                                                                         if(c[s-1]==0||c[s-1]==ct)c[s-1]=ct;                                                                                     else{                                                                                                                           c[0]=0;                                                                                                                 break;                                                                                                          }                                                                                                               }                                                                                                                       if(c[0]==0)cout << -1;                                                                                                  else rep(i,n)cout << c[i];                                                                                                                                                                                                                      return 0;                                                                                                       } 

Compiler output:
a.cc:1:121: warning: extra tokens at end of #include directive
    1 | #include<iostream>                                                                                                      using namespace std;                                                                                                    #define rep(i,n) for(int i=0;i<n;i++)                                                                                   #include<vector>                                                                                                                                                                                                                                                                                                                                                        int main(){                                                                                                                     int n,m;                                                                                                                cin >> n >> m;                                                                                                                                                                                                                                  int c[n],s,ct;                                                                                                          rep(i,n)c[i]=0;                                                                                                         rep(i,m){                                                                                                                       cin >> s >> ct;                                                                                                         if(c[s-1]==0||c[s-1]==ct)c[s-1]=ct;                                                                                     else{                                                                                                                           c[0]=0;                                                                                                                 break;                                                                                                          }                                                                                                               }                                                                                                                       if(c[0]==0)cout << -1;                                                                                                  else rep(i,n)cout << c[i];                                                                                                                                                                                                                      return 0;                                                                                                       }
      |                                                                                                                         ^~~~~
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x17): undefined reference to `main'
collect2: error: ld returned 1 exit status