diff options
Diffstat (limited to '3.5.c')
-rw-r--r-- | 3.5.c | 62 |
1 files changed, 62 insertions, 0 deletions
@@ -0,0 +1,62 @@ +#include <stdio.h> + +#define MAXLEN 15 + +void reverse(char str[]); +char* itob(int n, char str[], int base); + +int +main(void) +{ + int n = 21474836; + char str[MAXLEN]; + + printf("%x\n", n); + printf("%s\n", itob(n, str, 16)); + + return 0; +} + +void +reverse(char str[]) +{ + int i, j; + char temp; + + for (j = 0; str[j] != '\0'; j++) + ; + + for (i = 0, --j; i < j; i++, j--) { + temp = str[i]; + str[i] = str[j]; + str[j] = temp; + } +} + +char* +itob(int n, char str[], int base) +{ + int sign, i; + + /* to include the most -ve int */ + n = ((sign = n) < 0) ? -(n+1) : n-1; + + i = 0; + do { + if (n%base >= 0 && n%base <= 9) + str[i++] = n%base + '0'; + else + str[i++] = n%base + 'a' - 10; + } while ((n /= base) > 0); + + if (sign <0) + str[i++] = '-'; + + /* part of "to include the most -ve int" */ + str[0] += 1; + str[i] = '\0'; + + reverse(str); + + return str; +} |