我想输入一个连续的4个数的全排列，代码写成这样，哪里出错了呢？

#include<stdio.h>
int main()
{
    int i,j,k;
    int a;
    int cnt=0;
    scanf("%d",&a);
     
    for (i=a;i<=a+3;i++){
        
        for(j=a;j<=j+3;j++){
            
            for(k=a;k<=k+3;k++){
                if(i!=j && i!=j && j!=k)
                {
                    printf("%d%d%d",i,j,k);
                    cnt++;
                    if(cnt==6){
                        printf("\n");
                        cnt=0;
                    }
                    else{
                        printf(" ");
                    }
                }
            }
        }
    }
 }