text: #include <stdio.h>
  #include <time.h>
  int main() {
  	int num, Div;
  	clock_t start,finish;
  	double totalTime;
  	start = clock();
  	printf("1, 2");
  	for (num = 3; num <= 1000; num += 2) {
  		for(Div = 3; Div < num; Div +=2 ) {
  			if (num % Div == 0) {
  				break;
  			}
  		}
   
  		if(Div >= num) {
  			printf(", %d", num);
  		}
  	}
  	printf("\n");
  	finish = clock();
  	totalTime = (double)(finish-start) / CLOCKS_PER_SEC;
  	printf("打印的总时间为%.30f",totalTime);
  	return 0;
  }