leetcode-java/src/FindMinimumInRotatedSortedArray153.java at master · fluency03/leetcode-java · GitHub

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/**
 * Suppose an array sorted in ascending order is rotated at some pivot unknown
 * to you beforehand.
 *
 * (i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).
 *
 * Find the minimum element.
 *
 * You may assume no duplicate exists in the array.
 *
 * Example 1:
 *
 * Input: [3,4,5,1,2]
 * Output: 1
 * Example 2:
 *
 * Input: [4,5,6,7,0,1,2]
 * Output: 0
 *
 */


publicclassFindMinimumInRotatedSortedArray153 {
publicintfindMin(int[] nums) {
returnfindMin(nums, 0, nums.length-1);
 }

publicintfindMin(int[] nums, ints, inte) {
if (nums[s] <= nums[e]) returnnums[s];
intmid = (s + e) / 2;
returnMath.min(findMin(nums, s, mid), findMin(nums, mid+1, e));
 }


publicintfindMin2(int[] nums) {
ints = 0;
inte = nums.length-1;
while (s < e) {
intmid = (s + e) / 2;
if (nums[mid] > nums[e]) {
s = mid + 1;
 } else {
e = mid;
 }
 }
returnnums[e];
 }


publicintfindMin3(int[] nums) {
intstart = 0;
intend = nums.length - 1;
intstartVal = nums[start];
intendVal = nums[end];
while (start + 1 < end) {
intmid = start + (end - start) / 2;
if (nums[mid] > startVal) {
start = mid;
 } elseif (nums[mid] < endVal) {
end = mid;
 }
 }

returnMath.min(nums[end], Math.min(nums[start], Math.min(startVal, endVal)));
 }


publicintfindMin4(int[] nums) {
for (inti=1; i<nums.length; i++) {
if (nums[i] < nums[i-1]) returnnums[i];
 }
returnnums[0];
 }

}