c语言-leetcode 0012-roman-numeral.zip

#include <stdio.h> #include <stdlib.h> #include <string.h> static void num2char(char **num, int bit, int n) { int i; char low, mid, high; char *p = *num; switch (n) { case 2: low = 'C'; mid = 'D'; high = 'M'; break; case 1: low = 'X'; mid = 'L'; high = 'C'; break; case 0: low = 'I'; mid = 'V'; high = 'X'; break; } if (bit > 0) { switch (bit) { case 1: case 2: case 3: for (i = 0; i < bit; i++) { *p++ = low; } break; case 4: *p++ = low; *p++ = mid; break; case 5: *p++ = mid; break; case 6: case 7: case 8: *p++ = mid; for (i = 5; i < bit; i++) { *p++ = low; } break; case 9: *p++ = low; *p++ = high; break; } } *num = p; } static char roman_numeral[64] = { '\0' }; static char *intToRoman(int num) { int i; char *p = &roman_numeral[0]; int thousand_bit = num / 1000; int hundred_bit = (num % 1000) / 100; int ten_bit = (num % 100) / 10; int one_bit = num % 10; if (thousand_bit > 0) { if (thousand_bit < 4) { for (i = 0; i < thousand_bit; i++) { *p++ = 'M'; } } } num2char(&p, hundred_bit, 2); num2char(&p, ten_bit, 1); num2char(&p, one_bit, 0); *p = '\0'; return roman_numeral; } int main(int argc, char **argv) { printf("%s\n", intToRoman(atoi(argv[1]))); return 0; }