#include <bits/stdc++.h>
using namespace std;
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r){return l+rng()%(r-l+1);}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0);
#define forinc(a,b,c) for(int a=b,_c=c;a<=_c;++a)
#define fordec(a,b,c) for(int a=b,_c=c;a>=_c;--a)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<int,int>
#define mt make_tuple
#define all(a) a.begin(),a.end()
#define reset(f, x) memset(f, x, sizeof(f))
#define gg exit(0);
#include "wall.h"
void buildWall(int n,int k,vector<int> op,vector<int> l,vector<int> r,vector<int> h,vector<int> &ans){
}
/**
main(){
#define task "TASK"
if(fopen(task".inp","r")){
freopen(task".inp","r",stdin);
//freopen(task".out","w",stdout);
}
}
*/
Compilation message
/tmp/ccx7zwro.o: In function `main':
grader.cpp:(.text.startup+0x113): undefined reference to `buildWall(int, int, int*, int*, int*, int*, int*)'
collect2: error: ld returned 1 exit status
