#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main ()
{
   int x, y, xmax, ymax, champexists;

   /* Seed the random number generator by the current time. We get different
      random sequences in different runs. */
   srand((unsigned int)time(NULL));

   /* Initialize the variables. xmax stores the largest x-coordinate, and
      ymax the largest y-coordinate read so far. champexists is a flag
      indicating whether the champion exists or not in the current
      collection. */
   xmax = ymax = -1; champexists = 0;
   while (1) {
      /* Randomly decide whether to quit or generate a new point. */
      if (rand() % 20) {
         x = rand() % 1000; y = rand() % 1000;
      } else x = y = -1;
      printf("New point: (%3d, %3d). ", x, y);
      if ((x < 0) || (y < 0)) {
         printf("Quitting...\n");
         break;
      }
      if ((x >= xmax) && (y >= ymax)) { /* New champion found */
         champexists = 1; xmax = x; ymax = y;
      } else if (x > xmax) {            /* Here y < ymax but x > xmax */
         champexists = 0; xmax = x;
      } else if (y > ymax) {            /* Here x < xmax but y > ymax */
         champexists = 0; ymax = y;
      }
      printf("Current champion: ");
      if (champexists) printf("(%3d, %3d)\n", xmax, ymax);
      else printf("None\n");
   }

   exit(0);
}