remove comments from c/cpp prog

#include <stdio.h>
#define CAN_PRINT 0
#define MET_SLASH 1
#define MET_LINE_COMM 2
#define MET_BLOCK_COMM 3
#define MET_END_BLOCK_STAR 4


int main() {
  short state = CAN_PRINT;
  for (char ch; (ch = getchar()) != EOF;) {
    if (ch == '/' && state == CAN_PRINT) {
      state = MET_SLASH;
    } else if (ch == '/' && state == MET_SLASH)  {
      state = MET_LINE_COMM;
    } else if (ch == '*' && state == MET_SLASH) {
      state = MET_BLOCK_COMM;
    } else if (ch == '\n' && state == MET_LINE_COMM) {
      state = CAN_PRINT;
    } else if (ch == '*' && state == MET_BLOCK_COMM) {
      state = MET_END_BLOCK_STAR;
    } else if (ch == '/' && state == MET_END_BLOCK_STAR) {
      state = CAN_PRINT;
      continue;
    } else if (ch != '/' && state == MET_SLASH) {
      putchar('/');
      state = CAN_PRINT;
    } else if (ch != '/' && state == MET_END_BLOCK_STAR) {
      state = MET_BLOCK_COMM;
    }

    putchar(state == CAN_PRINT ? ch : 0);
  }
  return 0;
}