Problem p00009 (C++) — buggy submission, verdict: Time Limit Exceeded

/*
    ????????°??§???????????¨????????????
*/

#include <algorithm>
#include <ctype.h>
#include <iostream>
#include <iterator>
#include <limits.h>
#include <map>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <time.h>
#include <utility>
#include <vector>
#define LLU unsigned long long int
#define LL long long int
#define LD long double
using namespace std;
#define LLUmax ULLONG_MAX
#define LLmax LLONG_MAX
#define dmax INT_MAX
#define vd vector<int>
#define vLL vector<long long int>
#define vLLU vector<unsigned long long int>
#define pb push_back
#define mp make_pair
#define fi first
#define sec second
#define debug printf("asd\\n")
#define debugd(a) printf("--%d\\n", a)
#define debugdd(a, b) printf("--%d %d\\n", a, b)
#define debugarr(a, b)                                                         \\
  for (int i = 0; i < b; i++)                                                  \\
    printf("%d ", a[i]);                                                       \\
  printf("\\n")
#define newline printf("\\n")
#define forin(a, b, c) for (int a = b; a < c; a++)
#define forde(a, b, c) for (int a = b; a < c; a--)

inline void scd(int &a) { scanf("%d", &a); }
inline void scdd(int &a, int &b) { scanf("%d %d", &a, &b); }
inline void sctd(int &a, int &b, int &c) { scanf("%d %d %d", &a, &b, &c); }
inline void scdlld(long int &a, long int &b) { scanf("%I64d %I64d", &a, &b); }
inline void sclld(long long int &a) { scanf("%I64d", &a); }

#define scarrd(a, b)                                                           \\
  for (int index = 0; index < b; index++)                                      \\
  scanf("%d", &a[index])
#define prdlld(a, b) printf("%I64d %I64d", a, b)
#define prdd(a, b) printf("%d %d", a, b)
#define prd(a) printf("%d", a)
#define prarr(a, b)                                                            \\
  for (int i = 0; i < b; i++)                                                  \\
  printf("%d ", a[i])
#define iniarr(a, b)                                                           \\
  for (int i = 0; i < b; i++)                                                  \\
  a[i] = 0
#define arr(a, b) int *a = (int *)malloc(b * sizeof(int))
#define llarr(a, b)                                                            \\
  long long int *a = (long long int *)malloc(b * sizeof(long long int))
#define st(a, b) char *a = (char *)malloc(b * sizeof(char))
#define grav 9.8
#define pi 3.14159265

int prime(int a) {
  if (a < 2)
    return 1;

  for (int i = 2; (i * i) <= a; i++) {
    if (a % i == 0)
      return 0;
  }

  return 1;
}

int main() {
  int a;
  int pm[200005];
  int z = 0;
  forin(i, 2, 2000000) {
    if (prime(i) == 1) {
      pm[z] = i;
      z++;
    }
  }

  while (scanf("%d", &a) != EOF) {
    int d = 0;
    forin(i, 0, z) {
      if (pm[i] > a) {
        d = i;
        printf("%d\\n", d);
        break;
      }
    }
  }
  return 0;
}

Error: TLE

Fixed submission:

/*
    ????????°??§???????????¨????????????
*/

#include <algorithm>
#include <ctype.h>
#include <iostream>
#include <iterator>
#include <limits.h>
#include <map>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <time.h>
#include <utility>
#include <vector>
#define LLU unsigned long long int
#define LL long long int
#define LD long double
using namespace std;
#define LLUmax ULLONG_MAX
#define LLmax LLONG_MAX
#define dmax INT_MAX
#define vd vector<int>
#define vLL vector<long long int>
#define vLLU vector<unsigned long long int>
#define pb push_back
#define mp make_pair
#define fi first
#define sec second
#define debug printf("asd\\n")
#define debugd(a) printf("--%d\\n", a)
#define debugdd(a, b) printf("--%d %d\\n", a, b)
#define debugarr(a, b)                                                         \\
  for (int i = 0; i < b; i++)                                                  \\
    printf("%d ", a[i]);                                                       \\
  printf("\\n")
#define newline printf("\\n")
#define forin(a, b, c) for (int a = b; a < c; a++)
#define forde(a, b, c) for (int a = b; a < c; a--)

inline void scd(int &a) { scanf("%d", &a); }
inline void scdd(int &a, int &b) { scanf("%d %d", &a, &b); }
inline void sctd(int &a, int &b, int &c) { scanf("%d %d %d", &a, &b, &c); }
inline void scdlld(long int &a, long int &b) { scanf("%I64d %I64d", &a, &b); }
inline void sclld(long long int &a) { scanf("%I64d", &a); }

#define scarrd(a, b)                                                           \\
  for (int index = 0; index < b; index++)                                      \\
  scanf("%d", &a[index])
#define prdlld(a, b) printf("%I64d %I64d", a, b)
#define prdd(a, b) printf("%d %d", a, b)
#define prd(a) printf("%d", a)
#define prarr(a, b)                                                            \\
  for (int i = 0; i < b; i++)                                                  \\
  printf("%d ", a[i])
#define iniarr(a, b)                                                           \\
  for (int i = 0; i < b; i++)                                                  \\
  a[i] = 0
#define arr(a, b) int *a = (int *)malloc(b * sizeof(int))
#define llarr(a, b)                                                            \\
  long long int *a = (long long int *)malloc(b * sizeof(long long int))
#define st(a, b) char *a = (char *)malloc(b * sizeof(char))
#define grav 9.8
#define pi 3.14159265

int prime(int a) {
  if (a <= 2)
    return 1;

  if (a % 2 == 0)
    return 0;

  for (int i = 3; (i * i) <= a; i += 2) {
    if (a % i == 0)
      return 0;
  }

  return 1;
}

int main() {
  int a;
  while (scanf("%d", &a) != EOF) {
    int d = 0;
    forin(i, 2, a + 1) {
      if (prime(i) == 1)
        d++;
    }
    printf("%d\\n", d);
  }
  return 0;
}