text: #include <stdlib.h>
  
  int equalSubstring(char *s, char *t, int maxCost)
  {
  	int i = 0, j = 0, cost = 0;
  	for (; s[j]; ++j)
  	{
  		cost += abs(s[j] - t[j]);
  		if (cost > maxCost)
  		{
  			cost -= abs(s[i] - t[i]);
  			++i;
  		}
  	}
  	return j - i;
  }