majority

pfi2011.c

#include <stdio.h>
int main()
{
  char curr, next, ans;
  unsigned int cnt;

  for (curr = getchar();;curr = next) {
    if ((next = getchar()) == EOF || next == '\n') break;
    if (next == curr) {
      if (cnt == 0) ans = next;
      if (next == ans) {
        cnt++;
      } else {
        if (cnt > 0) cnt--;
        if (cnt == 0) ans = curr;
      }
    }
  }
  printf("Output: %c\n", (cnt > 0) ? ans : curr);
}