[1679] Max Number of K-Sum Pairs

Two sums 系列題連發？！

一次解完，開薰XD

int comp(const void* a, const void* b){

return (*(int *)a - *(int *)b);

}

int maxOperations(int* nums, int numsSize, int k){

qsort((void*)nums, numsSize, sizeof(int), comp);

int count =0;

int i=0, j=numsSize-1;

while (i<j)

{

int sum = nums[i]+nums[j];

if (sum ==k)

{

i++;

j--;

count++;

}

else if (sum<k)

i++;

else

j--;

}

return count;

}