程序代码：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define N 100000
int main()
{    
    int n=0;
    int i,j;
    printf("Please input n!");
    scanf("%d",&n);
    char hex[n][N];
    char oct[n][N];
    char oct2[n][N];
    printf("Please input oct!");
    for(i=0;i<n;i++)
    {
        gets(oct[i]);
        
    }
    for(i=0;i<n;i++)
    {
        for(j=0;j<strlen(oct[i]);j++)
        {
            switch(oct[i][j])
            {
                case'F':
                    oct2[i][j]="1111";
                    break;
                case 'E':
                    oct2[i][j]+="1110";
                    break;
                case 'D':
                    oct2[i][j]+="1101";
                    break;
                case 'C':
                    oct2[i][j]+="1100";
                    break;
                case 'B':
                    oct2[i][j]+="1011";
                    break;
                case 'A':
                    oct2[i][j]+="1010";
                    break;
                case '0':
                    oct2[i][j]+="0000";
                    break;
                case '1':
                    oct2[i][j]+="0001";
                    break;
                case '2':
                    oct2[i][j]+="0010";
                    break;
                case '3':
                    oct2[i][j]+="0011";
                    break;
                case '4':
                    oct2[i][j]+="0100";
                    break;
                case '5':
                    oct2[i][j]+="0101";
                    break;
                case '6':
                    oct2[i][j]+="0110"; 
                    break;
                case '7':
                    oct2[i][j]+="0111";
                    break;
                case '8':
                    oct2[i][j]+="1000";
                    break;
                case '9':
                    oct2[i][j]+="1001";
                    break;
                default:
                    break;
            }
        }
    }
    return 0;
}