java - Binary search condition -

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i'm confused condition of binary search algorithm , costs me lot of time in programming contests. question when use each of these conditions?
1. while (low < high)
2. while (high - low > 1)
3. while (low <= high)
low = lowest value in set of solutions.
high = largest value in set of solutions.

  1. while (low < high) used when you're searching range [low, high). when updating high, use high = mid. when updating low, use low = mid + 1.
  2. while (high - low > 1) used when you're searching range (low, high). when updating high, use high = mid. when updating low, use low = mid.
  3. while (low <= high) used when you're searching range [low, high]. when updating high, use high = mid - 1. when updating low, use low = mid + 1.

code below:

public class binarysearch {     public static void main(string[] args) {         integer[] nums = { 4, 9, 12, 18, 20, 26, 28, 29, 55 };          (int = 0; < nums.length; ++i) {             system.out.println(binarysearch1(nums, nums[i]));             system.out.println(binarysearch2(nums, nums[i]));             system.out.println(binarysearch3(nums, nums[i]));         }     }      public static <t extends comparable<t>> int binarysearch1(t[] array, t value) {         final int not_found = -1;         int low = 0;         int high = array.length;          while (low < high) {             int mid = low + (high - low) / 2;             int comparison = array[mid].compareto(value);              if (comparison == 0) {                 return mid;             } else if (comparison > 0) {                 high = mid;             } else {                 low = mid + 1;             }         }          return not_found;     }      public static <t extends comparable<t>> int binarysearch2(t[] array, t value) {         final int not_found = -1;         int low = -1;         int high = array.length;          while (high - low > 1) {             int mid = low + (high - low) / 2;             int comparison = array[mid].compareto(value);              if (comparison == 0) {                 return mid;             } else if (comparison > 0) {                 high = mid;             } else {                 low = mid;             }         }          return not_found;     }      public static <t extends comparable<t>> int binarysearch3(t[] array, t value) {         final int not_found = -1;         int low = 0;         int high = array.length - 1;          while (low <= high) {             int mid = low + (high - low) / 2;             int comparison = array[mid].compareto(value);              if (comparison == 0) {                 return mid;             } else if (comparison > 0) {                 high = mid - 1;             } else {                 low = mid + 1;             }         }          return not_found;     } }

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