The simulation generates random numbers and calculates the birthday of each student

When generating random numbers , I chose time（0）, But it can always generate the same random number . I began to attribute it to computers running too fast , A certain interval is required , So this random number can't be used . After consulting the boss , The reason is that srand（） and rand All in a loop . need srand Out of the loop ,rand Use together in the cycle , In this way, a real random number can be generated .

#include<iostream>
#include<stdlib.h>
#include<time.h>
using namespace std;
const float Day = 365.0;
int getrand();
int main()
{
    
	int birth[50] = {
     0 },i,j,l,k,flag,count=0;
	float p;
	srand((unsigned)time(0));
	for (j = 0; j < 10000; j++)
	{
    
		flag = 0;
		for (i = 0; i <50; i++)
		{
    
			birth[i] = rand()%365+1;
		}

		for (k = 0; flag == 0 && k <49; k++)
		{
    
			for (l = k + 1; l < 50; l++)
			{
    
				if (birth[k] == birth[l])
				{
    
					flag = 1;

					break;
				}

			}
		}
		if (flag == 1)
			count++;
		
	}
	cout << count<<endl;
    p = (float)count / j;
	p = 1 - p;
	cout << p;
	
	return 0;
}
``