Connect Four(C言語で４目並べ）

よくある４目並べです。
かなり幼稚なCPUのアルゴリズムなのでもっと強くしたい。
先攻はCPUです。
２０ターンCPUが持ちこたえたら僕の勝ち。

#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>

void  displayMatrix (int matrix[7][6])
{
    int   row, column;

    for ( column = 5;  column >= 0;  --column) {
        for ( row = 0;  row < 7;  ++row )
            printf ("%5i", matrix[row][column]);
        printf ("\n");
    }
}

//
// the function that checks there are vertical connection or not
// same algorithm for vertical, horizontal and diagonal
// amount = how many connections
//
int vertical(int cpu, int player, int amount, int table[7][6])
{
  for (int i = 0; i < 7; ++i)
  {
    cpu = 0;
    player = 0;
    for (int h = 0; h < 6; ++h)
    {
      if(cpu == amount)
      {
        return 1;
      }
      else if(player == amount)
      {
        return 2;
      }

      if(table[i][h] == 1){
      cpu += 1;
      player = 0;
      }
      else if(table[i][h] == 2){
        player += 1;
        cpu = 0;
      }
      else{
        cpu = 0;
        player = 0;
      }
    }
  }

  return 0;
}

int horizontal(int cpu, int player, int amount, int table[7][6])
{
  for (int h = 0; h < 6; ++h)
  {
    cpu = 0;
    player = 0;
    for (int i = 0; i < 7; ++i)
    {
      if(cpu == amount)
      {
        return 1;
      }
      else if(player == amount)
      {
        return 2;
      }

      if(table[i][h] == 1){
        cpu += 1;
        player = 0;
      }
      else if(table[i][h] == 2){
        player += 1;
        cpu = 0;
      }
      else{
        cpu = 0;
        player = 0;
      }
    }
  }

  return 0;
}

int diagonal(int cpu, int player, int amount, int table[7][6])
{
  for (int i = 0; i < 7; ++i)
  {
    cpu = 0;
    player = 0;
    for (int h = 0, k = 0; h < 7, k < 6; ++h, ++k)
    {
      int point = table[i + h][k];
      if(cpu == amount)
      {
        return 1;
      }
      else if(player == amount)
      {
        return 2;
      }

      if(point == 1){
        ++cpu;
        player = 0;
      }
      else if(point == 2){
        ++player;
        cpu = 0;
      }
      else{
        cpu = 0;
        player = 0;
      }
    }
  }

  cpu = 0;
  player = 0;

  for (int i = 6; i >= 0; --i)
  {
    cpu = 0;
    player = 0;
    for (int h = 0, k = 0; h < 7, k < 6; ++h, ++k)
    {
      int point = table[i - h][k];
      if(cpu == amount)
      {
        return 1;
      }
      else if(player == amount)
      {
        return 2;
      }

      if(point == 1){
        ++cpu;
        player = 0;
      }
      else if(point == 2){
        ++player;
        cpu = 0;
      }
      else{
        cpu = 0;
        player = 0;
      }
    }
  }

  for (int i = 1; i < 3; ++i)
  {
    cpu = 0;
    player = 0;
    for (int h = 0, k = 0; h < 5, k < 6; ++h, ++k)
    {
      int point = table[h][i + k];
      if(cpu == amount)
      {
        return 1;
      }
      else if(player == amount)
      {
        return 2;
      }

      if(point == 1){
        ++cpu;
        player = 0;
      }
      else if(point == 2){
        ++player;
        cpu = 0;
      }
      else{
        cpu = 0;
        player = 0;
      }
    }
  }

  for (int i = 6; i >= 0; --i)
  {
    cpu = 0;
    player = 0;
    for (int h = 0, k = 1; h < 7, k < 6; ++h, ++k)
    {
      int point = table[i - h][k];
      if(cpu == amount)
      {
        return 1;
      }
      else if(player == amount)
      {
        return 2;
      }

      if(point == 1){
        ++cpu;
        player = 0;
      }
      else if(point == 2){
        ++player;
        cpu = 0;
      }
      else{
        cpu = 0;
        player = 0;
      }
    }
  }

  return 0;
}

// function for just create random number between min and max
int random_number(int min, int max)
{
  return min + (int)(rand()*(max - min + 1.0) / (1.0 + RAND_MAX));
}

// checks there are crucial hand or not
int check_mate(int number, int column_number, int table[7][6], int side)
{
  // checking cpu's hands
  for (number = 0; number < 7; ++number)
  {
    column_number = 7;
    for (int i = 0; i < 6; ++i){
      if (table[number][i] == 0){
        table[number][i] = side;
        column_number = i;
        break;
      }
    }
    if(column_number != 7){
      if (vertical(0, 0, 4, table) == side || horizontal(0, 0, 4, table) == side || diagonal(0, 0, 4, table) == side){
        if (side == 2)
        {
          table[number][column_number] = 1;
        }
        return 1;
      }
      else{
        table[number][column_number] = 0;
      }
    }
  }
  return 0;
}

int main(int argc, char const *argv[])
{
  void displayMatrix(int matrix[7][6]);
  int vertical(int cpu, int player, int amount, int table[7][6]);
  int horizontal(int cpu, int player, int amount, int table[7][6]);
  int diagonal(int cpu, int player, int amount, int table[7][6]);
  int check_mate(int cpu_number, int column_number, int table[7][6], int side);
  int connect[7][6] =
          {
              { 0, 0, 0, 0, 0, 0 },
              { 0, 0, 0, 0, 0, 0 },
              { 0, 0, 0, 0, 0, 0 },
              { 1, 0, 0, 0, 0, 0 },
              { 0, 0, 0, 0, 0, 0 },
              { 0, 0, 0, 0, 0, 0 },
              { 0, 0, 0, 0, 0, 0 },
          };
  int count = 0, player_number = 0, cpu_number = 0, column_number = 0;

  printf("    ∧,,∧\n   ( 'ω' )つ Game Start!!!\n   （m9 ＼ \n     ＼   ＼\n        ) ) ＼\n      ／／ ＼ ＼\n     (＿）   (＿)\n");
  // game start
  while(true){
    printf("count: %i\n", count);
    printf("-------------------------------------\n");
    printf("    1    2    3    4    5    6    7\n");
    printf("-------------------------------------\n");
    displayMatrix (connect);

    // check
    int cpu = 0, player = 0;
    if (vertical(cpu, player, 4, connect) == 1 || horizontal(cpu, player, 4, connect) == 1 || diagonal(cpu, player, 4, connect) == 1){
      printf("         nn\n      （´･ω･）\n    ＿|  ⊃／(＿＿_\n  ／  └-(＿＿＿_／\n  ￣￣￣￣￣￣￣\nYou LOSE....");
      return 0;
    }
    else if(vertical(cpu, player, 4, connect) == 2 || horizontal(cpu, player, 4, connect) == 2 || diagonal(cpu, player, 4, connect) == 2)
    {
      printf("      ☆ *  .   ☆ \n    ☆  . ∧＿∧  n  * ☆ \n  kt━━━( ・∀・)/ . ━━━!!\n     . ⊂     ノ* ☆ \n   ☆ * (つ ノ .☆ \n       (ノ\n     You WIN!!!!\n");
      return 0;
    }

    // play
    // 1: put 0 into number
    // 2: check cpu has check mate move or not
    // 3: check player has check mate move
    // 4: loop it until 6
    // 5: if there are no check mate move, put random number into number
    if (count % 2 == 1)
    {
      // cpu's turn
      int cpu = 0, player = 0;

      if (check_mate(0, 0, connect, 1)){
        printf("are you serious?\n");
      }
      else if(check_mate(0, 0, connect, 2)){
        printf("close!\n");
      }
      else{
        cpu_number = random_number(0, 6);
        for (int i = 0; i < 6; ++i){
          if (connect[cpu_number][i] == 0){
            connect[cpu_number][i] = 1;
            break;
          }
        }
      }
    }
    else{
      // player's turn
        printf("Your Turn\n");
        printf("put in your peg\n");
        printf("Press (only) 1 ~ 7\n");
        scanf  ("%i", &player_number);
        for (int i = 0; i < 6; ++i){
          if (connect[player_number - 1][i] == 0){
            connect[player_number - 1][i] = 2;
            break;
          }
        }
    }
    count += 1;
  }

  return 0;
}

冬休み入ったらもっとかっこいいコードに修正しよ