剑指offer 最小的K个数

public ArrayList<Integer> GetLeastNumbers_Solution(int [] input, int k) {
if (input == null || input.length ==0) {
return new ArrayList<>();
}
if (input.length < k || k == 0) {
return new ArrayList<>();
}
ArrayList<Integer> result = new ArrayList<>(k);
for (int i = k,len = input.length; i < len; i++) {
int maxIndex = getMaxIndex(input,k);
if (input[maxIndex] > input[i]) {
input[maxIndex] = input[i];
}
}
for (int i = 0; i < k; i++) {
result.add(input[i]);
}
return result;
}

public int getMaxIndex(int[] input,int k) {
int index = 0;
int max = input[0];
for (int i = 1; i < k; i++) {
if (max < input[i]) {
index = i;
max = input[i];
}
}
return index;
}