Spiralna upis matrice

#include <stdio.h>
main(){
    int a[12][12],b[12][12], n, m, i, j;
    FILE *fp, *f;
    fp = fopen("matrica.txt","r");
    fscanf(fp," %d",&n);
    fscanf(fp," %d",&m);
    for(i=0;i<n;i++){
        for(j=0;j<m;j++){
            fscanf(fp," %d", &a[i][j]);
        }
    }
    fclose(fp);
    f = fopen("odradi.txt","w");
    int rs=0, cs=0;
    int re=n-1, ce=n-1;
    while(rs<=re && cs<=ce) {
        int i=rs, j=cs;
        for(j=cs; j<=ce; j++){
            fprintf(f," %d",a[i][j]);
        }
        for(i=rs+1, j--; i<=re; i++){
            fprintf(f," %d",a[i][j]);
        }
        for(j=ce-1, i--; j>=cs; j--){
            fprintf(f," %d",a[i][j]);
        }
        for(i=re-1, j++; i>=rs+1; i--){
            fprintf(f," %d",a[i][j]);
        }
        rs++;
        cs++;
        re--;
        ce--;
    }
    fclose(fp);
    f = fopen("odradi.txt","r");
    for(i=0;i<n;i++)
    {
        for(j=0;j<m;j++)fscanf(f," %d",&b[i][j]);
    }
    for(i=0;i<n;i++)
    {
        printf("\n");
        for(j=0;j<m;j++)printf(" %d",b[i][j]);
    }

}