代码如下：

#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>int dectohex(int b, char array[])
{char a[17] = { "0123456789ABCDEF" };int c[30] = { 0 }, i = 0, base = 16, j = 0;while (b){c[i++] = b % base;b = b / base;}j = i;for (i--; i >= 0; i--)array[i] = a[c[i]];return j;
}int main()
{char arr[100];int b = 0, n = 0;printf("请输入一个十进制数\n");scanf("%d", &b);n = dectohex(b, arr);printf("%d的十六进制为:", b);for (n--; n >= 0; n--)printf("%c", arr[n]);
}

结果如下：