【剑指offer】之数字在排序数组中出现的次数

//统计出现的次数
private static int getNumber(int[]nums,int k) {
int firstindex = findFirst(nums,0,nums.length-1,k);
int lastindex = findlast(nums,0,nums.length-1,k);

return lastindex-firstindex+1;
}

private static int findFirst(int []nums,int start ,int end,int targetNumber) {

int middle = (start + end) / 2;

if(nums[middle] == targetNumber) {
if(middle == 0 ||(nums[middle-1]!=targetNumber && middle>0)) {
return middle;
} else {
end = middle - 1;
}
}

if(nums[middle] >= targetNumber)
end = middle -1;
else
start = middle + 1;

return findFirst(nums,start ,end,targetNumber) ;
}

private static int findlast(int []nums,int start ,int end,int targetNumber) {

int middle = (start + end) / 2;

if(nums[middle] == targetNumber) {
if(middle == nums.length-1 ||(nums[middle+1]!=targetNumber && middle<nums.length-1)) {
return middle;
} else {
start = middle + 1;
}
}

if(nums[middle] <= targetNumber)
start = middle +1;
else
end = middle - 1;

return findlast(nums,start ,end,targetNumber) ;
}

public static void main(String[] args) throws FileNotFoundException {
int [] numbers = {1,2,3,3,3,3,4,5};

System.out.println(getNumber(numbers,3));
}