Language: C

#include<stdio.h>
#include<string.h>

#define M 1046527
#define NIL (-1)
#define L 14

char H[M][L];

int getChar(char c){
  if(c == `A`) return 1;
  else if(c == `C`) return 2;
  else if(c == `G`) return 3;
  else if(c == `T`) return 4;
  else return 0;
}

long long getKey(char str[]){
  long long sum = 0, p = 1, i;
  for(i = 0; i < strlen(str); i++){
    sum+= p * (getChar(str[i]));
    p *= 5;
  }
  return sum;
}

int h1(int key){ return key % M; }
int h2(int key){ return 1 + (key % (M - 1)); }

int find(char str[]){
  long long key, i, h;
  key = getKey(str[str]);
  for(i = 0; ; i++){
    h = (h1(key) + i * h2(key)) % M;
    if(strcmp(H[h], str) == 0) return 1;
    else if(strlen(H[h]) == 0) return 0;
  }
  return 0;
}

int insert(char str[]){
  long long key, i, h;
  key = getKey(str);
  for( i = 0; ; i++){
    h = (h1(key) + i * h2(key)) % M;
    if(strcmp(H[h], str) == 0) return 1;
    else if(strlen(H[h]) == 0){
      strcpy(H[h], str);
      return 0;
    }
  }
  return 0;
}

int main(){
  int i, n, h;
  char str[L], com[9];
  for(i = 0; i < M; i++) H[i][0] = `?\0`
  scanf("%d", &n);
  for(i = 0; i < n; i++){
    scanf("%s %s", com, str);
    if(com[0] == `i`){
      insert(str);
    }
    else{
      if(find(str)){
        printf("yes?\n");
      }
      else printf("no?\n");
    }
  }
  return 0;
}

Compiler output:
main.c: In function 'getChar':
main.c:11:11: error: stray '`' in program
   11 |   if(c == `A`) return 1;
      |           ^
main.c:11:13: error: stray '`' in program
   11 |   if(c == `A`) return 1;
      |             ^
main.c:11:12: error: 'A' undeclared (first use in this function)
   11 |   if(c == `A`) return 1;
      |            ^
main.c:11:12: note: each undeclared identifier is reported only once for each function it appears in
main.c:12:16: error: stray '`' in program
   12 |   else if(c == `C`) return 2;
      |                ^
main.c:12:18: error: stray '`' in program
   12 |   else if(c == `C`) return 2;
      |                  ^
main.c:12:17: error: 'C' undeclared (first use in this function)
   12 |   else if(c == `C`) return 2;
      |                 ^
main.c:13:16: error: stray '`' in program
   13 |   else if(c == `G`) return 3;
      |                ^
main.c:13:18: error: stray '`' in program
   13 |   else if(c == `G`) return 3;
      |                  ^
main.c:13:17: error: 'G' undeclared (first use in this function)
   13 |   else if(c == `G`) return 3;
      |                 ^
main.c:14:16: error: stray '`' in program
   14 |   else if(c == `T`) return 4;
      |                ^
main.c:14:18: error: stray '`' in program
   14 |   else if(c == `T`) return 4;
      |                  ^
main.c:14:17: error: 'T' undeclared (first use in this function)
   14 |   else if(c == `T`) return 4;
      |                 ^
main.c: In function 'find':
main.c:32:19: error: array subscript is not an integer
   32 |   key = getKey(str[str]);
      |                   ^
main.c: In function 'main':
main.c:58:36: error: stray '`' in program
   58 |   for(i = 0; i < M; i++) H[i][0] = `?\0`
      |                                    ^
main.c:58:37: error: expected expression before '?' token
   58 |   for(i = 0; i < M; i++) H[i][0] = `?\0`
      |                                     ^
main.c:58:38: error: stray '\' in program
   58 |   for(i = 0; i < M; i++) H[i][0] = `?\0`
      |                                      ^
main.c:58:40: error: stray '`' in program
   58 |   for(i = 0; i < M; i++) H[i][0] = `?\0`
      |                                        ^
main.c:62:18: error: stray '`' in program
   62 |     if(com[0] == `i`){
      |                  ^
main.c:62:20: error: stray '`' in program
   62 |     if(com[0] == `i`){
      |                    ^