Question

How to calculate the first N (random up to 100) prime numbers in C++

Answer 1

#include <iostream>
#include <cstdlib>
#include <ctime>

#define N 20

using namespace std;

int main()
{
	srand((unsigned)time(NULL));

	int n = rand() % 100 + 1;

	if (n >= 1)
	{
		printf("First %d prime numbers are:\n", n);
		printf("2\n");
	}

	int numbers, i, prime = 3;
	
	for (numbers = 2; numbers <= n;)
	{
		for (i = 2; i <= prime - 1; i++)
		{
			if (prime % i == 0)
				break;
		}
		if (i == prime)
		{
			cout << prime << endl;
			numbers++;
		}
		prime++;
	}

	return 0;
}


/*
run:

First 73 prime numbers are:
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47
53
59
61
67
71
73
79
83
89
97
101
103
107
109
113
127
131
137
139
149
151
157
163
167
173
179
181
191
193
197
199
211
223
227
229
233
239
241
251
257
263
269
271
277
281
283
293
307
311
313
317
331
337
347
349
353
359
367

*/

 

70+ SQL courses for beginners and professionals