"C Language" writing function implementation: 100-200 prime number of output __ function

In this, you first need to understand how prime is obtained, you can divide yourself by 2 to your previous position, according to the remainder of the situation to determine whether a prime or composite.

Optimization:

(1) Starting from 101, each time add 2, so as to improve the efficiency of one times.

(2) divided by its own square root can also be.

#include <stdio.h> #include <math.h> #include <stdlib.h> void prime () {   
 int num = 100;
    int k = 0;

    int i = 2;     for  (num = 101; num < 201; num++)   

  {        k = num / 2;         for  (;  i < num; i++)          {             if  (num % i != 0)    //all integers not--> primes, output, start to judge next number              {         
       printf ("%d    ",  num);                 break;             }              else       //can be divisible by a number--> composite numbers, Then this number can't be Sue lost, start judging the next number             {  
              break;             }       

&NBSP;&NBSP}    &nbsp}} int main () {    prime ();
    system ("pause");
    return 0; }