1287. Elements that appear more than 25% in an ordered array

【 Simple 】 Give you a non decreasing Orderly An array of integers , It is known that there is exactly one integer in this array , It occurs more than the total number of elements in the array 25%.

Please find and return this integer

Example ：

 Input ：arr = [1,2,2,6,6,6,6,7,10]
 Output ：6
 

Tips ：

1 <= arr.length <= 10^4
0 <= arr[i] <= 10^5

Solution 1 ：

 public int m1(int[] arr) {
    
        int target = 0;
        int start = 0;
        int x = arr.length / 4;//25%
        for (int i = 0; i < arr.length; i++) {
    
            if (arr[i] != target) {
    
                start = i;
                target = arr[i];
            }
            if (i - start + 1 > x)
                return target;
        }
        return target;
    }

Solution 2 ：

public int m2(int[] arr) {
    
        int threshold = arr.length / 4;//25%
        for (int i = 0; i < arr.length; i++) {
    
            if(arr[i + threshold] == arr[i])
                return arr[i];
        }
        return 0;
    }

Solution 3 ： Hash map

Map<Integer, Integer> map = new HashMap();
        for(int i : arr){
    // First, store the data in the array in map in ,key Element value ,value Is the number of occurrences 
            map.put(i, map.getOrDefault(i, 0) + 1);
        }
        for(int key : map.keySet()){
    
            Integer value = map.get(key);
            if(value > arr.length / 4){
    // Timely output if there are satisfied 
                return key;
            }
        }
        return -1;