#include <stdio.h> void main() { int k,n,m; printf("Enter an integer M: \n"); scanf_s("%d",&m); for(n = 2; n <= m; n++)/*outer loop begins*/ { for(k = 2; k <= n-1; k++)/*inner loop begins*/ { if(n%k == 0) break;/*若是條件爲真,跳出內循環直接執行下個語句;若是條件爲假,繼續執行內循環k++*/ } /*inner loop ends*/ if(k >= n) printf("%4d",n); } /*outer loop ends*/ }