输入小于等于十六位的二进制数据，输出十六进制数据；

#include <stdio.h>
#include <stdlib.h>
#include <math.h>int main(void) {char arr[16] = { 0 }; int array[16] = { 0 }; int hex[4] = { 0 };int i = 0; int  num = 0;scanf("%s", arr);printf("%s\n", arr);while (arr[i] != '\0'){i++;}printf("%d\n", i);        //arr[16]={'1','0','0','1','1','0','\0', , , ... , , , }int len = 16 - i;for (int k = i; k >= 0; k--)                 //往后移 arr[16]={'\0', '\0',  ... ,'\0' ,'\0' ,'1','0','0','1','1','0', }{                                    arr[k + len] = arr[k];}                                                           //arr[15-i]for (int d = 0; d < len; d++)         //前面的填充为'0'{                                            arr[d] = '0';}for (int j = 0; j < 16; j++) {array[j] = arr[j] - '0';}for (int s = 0; s < 16; s++)    //array[16]={0,0,0,0,0,0,0,0,1,0,0,1,1,0,0,1}{                   printf("array[s]=%d\n", array[s]);}for (int c = 15; c >= 0; c--) {int l = 0;if (array[c] != 0) {l = 15 - c; int x = 0;if (l < 4) {x = l % 4;hex[0] = hex[0] + pow(2, x);}if (l >= 4 && l < 8) {x = (l - 4) % 8;hex[1] = hex[1] + pow(2, x);}if (l >= 8 && l < 12) {x = (l - 8) % 12;hex[2] = hex[2] + pow(2, x);}if (l >= 12 && l < 16) {x = (l - 12) % 16;hex[3] = hex[3] + pow(2, x);}}}char ar[16] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' };printf("16radix:%c%c%c%c", ar[hex[3]], ar[hex[2]], ar[hex[1]], ar[hex[0]]);return 0;
}

生成十六进制的部分有点绕，所以写了个新的，空了补上算法的思路.

#include <stdio.h>
#include <stdlib.h>
#include <math.h>int main(void) {char arr[16] = { 0 }; int array[16] = { 0 },array_new[16]={0};int hex[4] = { 0 };int i = 0; scanf("%s", arr);printf("输入为：%s\n", arr);         //假设输入为：arr[16]={'1','1','0','1','1','0','\0', , , ... , , , }while (arr[i] != '\0'){i++;}printf("输入位数=%d\n", i);        int len = 16 - i;for (int k = i; k >= 0; k--)                 //往后移 arr[16]={'\0', '\0',  ... ,'\0' ,'\0' ,'1','1','0','1','1','0','0' }{                                    arr[k + len] = arr[k];}                                                           //arr[15-i]for (int d = 0; d < len; d++)         //前面的填充为'0'{                                            arr[d] = '0';}for (int j = 0; j < 16; j++) {array[j] = arr[j] - '0';         //char数字 to int数字； }for(int i=0;i<16;i++)              //array_new[16]={0,0,1,1,0,1,1，0,0,0,0,0,0,0,0,0}{         array_new[i]=array[15-i];}  for(int k=0;k<16;k++)       //倒序生成array_new;{if((k<4)&&(array_new[k]==1)){hex[3]=hex[3]+pow(2,k);}if(((k>=4)&&(k<8))&&(array_new[k]==1)){hex[2]=hex[2]+pow(2,k-4);}if(((k>=8)&&(k<12))&&(array_new[k]==1)){hex[1]=hex[1]+pow(2,k-8);}if(((k>=12)&&(k<16))&&(array_new[k]==1)){hex[0]=hex[0]+pow(2,k-12);}}printf("\n");char ar[16] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' };printf("16radix:%c%c%c%c", ar[hex[3]], ar[hex[2]], ar[hex[1]], ar[hex[0]]);return 0;
}