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FindPeakElement.java
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55 lines (50 loc) · 1.05 KB
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/**
*
*/
package cc.dectinc.leetcode;
/**
* @author chenshijiang
* @date Apr 20, 2015 4:25:10 PM
*
*/
public class FindPeakElement {
public int findPeakElementNaive(int[] nums) {
int length = nums.length;
if (length == 0) {
return Integer.MIN_VALUE;
} else if (length == 1) {
return 0;
} else {
if (nums[0] > nums[1]) {
return 0;
} else if (nums[length - 1] > nums[length - 2]) {
return length - 1;
}
}
for (int i = 1; i < length - 1; i++) {
if (nums[i] > nums[i - 1] && nums[i] > nums[i + 1]) {
return i;
}
}
return -1;
}
public int findPeakElement(int[] num) {
int start = 0;
int end = num.length - 1;
while (start < end) {
int mid = (start + end) / 2;
if (num[mid] < num[mid + 1]) {
start = mid + 1;
} else {
end = mid;
}
}
return start;
}
public static void main(String[] args) {
FindPeakElement sol = new FindPeakElement();
int[] numArray = { 1, 2, 3 };
// System.out.println(sol.findPeakElement(numArray));
System.out.println(sol.findPeakElementNaive(numArray));
}
}