[540] Single Element in a Sorted Array

啊......我果然是個無法考慮所有case的孩子啊QQ 

int singleNonDuplicate(int* nums, int numsSize) {

int l=0;

int r= numsSize-1;

if (numsSize==1)

return nums[0];

if (nums[0]!= nums[1])

return nums[0];

if (nums[numsSize-1]!= nums[numsSize-2])

return nums[numsSize-1];

int mid;

while (l<r)

{

mid = l+(r-l)/2;

// if (mid ==0 || mid == numsSize-1)

// break;

if ((nums[mid]!=nums[mid-1]) && nums[mid]!=nums[mid+1])

return nums[mid];

if (mid%2 !=0)

{

if (nums[mid]==nums[mid-1])

l=mid;

else if (nums[mid]==nums[mid+1])

r=mid;

}

else

{

if (nums[mid]==nums[mid-1])

r=mid;

else if (nums[mid]==nums[mid+1])

l=mid;

}

}

return -1;

}