C Exercise Example 1
Title:Yes1、2、3、4With four digits, how many three-digit numbers with distinct and non-repeating digits can be formed? What are they?
Program analysis:The digits that can be placed in the hundreds, tens, and ones places are all1、2、3、4After forming all permutations, remove those that do not meet the conditions.
Example
#include<stdio.h>
int main()
{
int i,j,k;
printf("\n");
for(i=1;i<5;i++) { // The following is a triple loop
for(j=1;j<5;j++) {
for (k=1;k<5;k++) { // Ensure i, j, k are all different
if (i!=k&&i!=j&&j!=k) {
printf("%d,%d,%d\n",i,j,k);
}
}
}
}
}
The output of the above example is:
1,2,3 1,2,4 1,3,2 1,3,4 1,4,2 1,4,3 2,1,3 2,1,4 2,3,1 2,3,4 2,4,1 2,4,3 3,1,2 3,1,4 3,2,1 3,2,4 3,4,1 3,4,2 4,1,2 4,1,3 4,2,1 4,2,3 4,3,1 4,3,2other extensions