Closest Number in Sorted Array
给出一个target,找出数组中与这个值最接近的值
public int closestNumber(int[] A, int target) {
// Write your code here
if(A == null || A.length == 0){
return -1;
}
int start = 0;
int end = A.length - 1;
while(start + 1 < end){
int mid = start + (end - start)/2;
if( A[mid] < target){
start = mid;
}else if (A[mid] == target){
return mid;
}else{
end = mid;
}
}
if(A[start] <= target && A[end] >= target){
return Math.abs(A[start] - target) > Math.abs(A[end] - target)?end:start;
}else if(A[end] < target){
return end;
}else{
return start;
}
}
K Closest Numbers In Sorted Array
find index, left pointer, right pointer and
```
public int[] kClosestNumbers(int[] A, int target, int k) {
int[] result = new int[k];
if ( A == null || A.length == 0 || k == 0 ) return result;
int left = findIndex(A, target) - 1;
int right =findIndex(A, target) + 1;
result[0] = A[findIndex(A, target)];
int index = 1;
while (left >= 0 && right <= A.length - 1&& index < k ){
if ( Math.abs( A[left] - target) <= Math.abs(A[right] - target)){
result[index] = A[left];
left--;
}else{
result[index] = A[right];
right++;
}
index++;
}
if ( index == k) return result;
if ( left < 0 && right < A.length){
while(right < A.length && index < k){
result[index] = A[right];
right++;
index++;
}
return result;
}else if ( right >= A.length && left >= 0 ){
while(left >= 0 && index < k){
result[index] = A[left];
left--;
index++;
}
return result;
}
return result;
}
public int findIndex( int[] A, int target){
int start = 0;
int end = A.length - 1;
while ( start + 1 < end){
int mid = start + (end - start) / 2;
if ( A[mid] == target ) return mid;
else if ( A[mid] < target){
start = mid;
}
else {
end = mid;
}
}
if ( A[start] >= target) return start;
else if ( A[end] <= target) return end;
else return Math.abs( A[start] - target) > Math.abs(A[end] - target)? end:start;
}
```