How to store characters in an int array?

Question

MySQL

Hello!
Here is the code below. How to keep characters in int array after input? Is it possible? Is this correct or do I need to create a 2nd char array?

#include "stdio.h"

int main() {
  int i, j, a[9][9], c = 1, n = 5, x = 0;
  for (i = 0; i < 9; i++) {
    for (j = 0; j < 9; j++) {
      a[i][j] = c++;
      printf("%0.2d ", a[i][j]);
    } 
    printf("\n");
  }
  
  while(n>0) {
    printf("Input number: ");
    scanf("%d", &x);
    for (i = 0; i < 9; i++) {
      for (j = 0; j < 9; j++) {
        if(a[i][j] == x) {
          a[i][j] = 'P';
          printf("(%c) ", a[i][j]);
          continue;
        }
        printf("%0.2d ", a[i][j]);
      } 
      printf("\n");
    }
    n--;
  }
  return 0;
}

Answer 1

one.

the request is executed in 22ms:

- I would test a more realistic scenario - how long does XX queries take - eg with https://dev.mysql.com/doc/refman/8.0/en/mysqlslap.html
2. How many indexes are on this table?
3.

CentOS, AMD 8 cores (don't remember the model), 64 GB RAM, SSD disks

- what is innodb_buffer_pool_size?
4. let's check the runtime with "insert" instead of update

Answer 2

set syn_binlog=0 and innodb_flush_log_at_trx_commit=2.
Please report the result.

Answer 3

Look at the connection to the database. Alternatively, connect to it by ip if you connect through the hostname

Answer 4

Have you tried different IO schedulers?
If there is a swap on the server, how many mysql pages are in the swap? Have you tried to test with the swap turned off?

Answer 5

Yes, you can do that, because it charis also an integer data type. And the variable stores the symbol number in the symbol table. Accordingly, in order to use these values ​​as symbols later, you need to convert them to the char.
Here is an example:

#include <iostream>

using namespace std;

int main()
{
    int i;
    char c;

    cin >> i;
    cin >> c;

    cout << i << endl;
    cout << c << endl;

    i = c;

    cout << i << endl;
    cout << char(i) << endl;
  
    return 0;
}