Following is my solutions with 26 test cases passed in 4ms. It's direct and easy to understand.

```
public int thirdMax(int[] nums) {
int max = Integer.MIN_VALUE, secondMax = Integer.MIN_VALUE, thirdMax = Integer.MIN_VALUE;
boolean hasThirdMax = false;
for (int i = 0; i < nums.length; i++) {
if (nums[i] > max) {
max = nums[i];
}
}
for (int i = 0; i < nums.length; i++) {
if (nums[i] > secondMax && nums[i] < max) {
secondMax = nums[i];
}
}
for (int i = 0; i < nums.length; i++) {
if (nums[i] >= thirdMax && nums[i] < secondMax) {
thirdMax = nums[i];
hasThirdMax = true;
}
}
return hasThirdMax ? thirdMax : max;
}
```

Waiting for your comments , guys.