4x4배열을 선언하고 배열요소들을 90도씩 이동하는 프로그램인데요 ..
제가 보기에도 조잡(?)하게 짠거같아서 .. 짜놓고봐도 뭔가 찜찜한데요 ..
C언어 고수분들이 보기엔 어떠신가요?;

#include <stdio.h>

int main(){
        int arr[4][4]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};
        int arr1[4][4];
        int i,j,n;

        for(i=0;i<4;i++){
                for(j=0;j<4;j++)
                        printf("%3d",arr[i][j]);
                printf("\n");
        }
        
        for(n=0;n<3;n++){
                for(i=0;i<4;i++){
                        for(j=0;j<4;j++)
                                arr1[i][j]=arr[i][j];
                }
                for(i=0;i<4;i++){
                        arr[i][3]=arr1[0][i];
                        arr[i][2]=arr1[1][i];
                        arr[i][1]=arr1[2][i];
                        arr[i][0]=arr1[3][i];
                }        
                printf("\n");

                for(i=0;i<4;i++){
                        for(j=0;j<4;j++)
                                printf("%3d",arr[i][j]);
                        printf("\n");
                }
        }
        
        return 0;
}