[1637] Widest Vertical Area Between Two Points Containing No Points

給一組(x,y), 雖然題目寫了一段，但意思就是求兩兩x 之間的最遠距離, y可以完全不管。

所以偷吃步就是～～～弄一個x array出來做sorting XD 但這樣當然慢一點

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

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

}

int maxWidthOfVerticalArea(int** points, int pointsSize, int* pointsColSize){

int *sortX=calloc(pointsSize, sizeof(int));

for (int i=0; i<pointsSize; i++)

sortX[i]=points[i][0];

qsort( (void *)sortX, pointsSize, sizeof(int), comp);

int diff=0;

for (int i=1;i<pointsSize;i++)

if (sortX[i]-sortX[i-1]>diff)

diff = sortX[i]-sortX[i-1];

return diff;

}

所以～～～～應該要改寫qsort的comp function ?!

sorting 二維的部分, 用先宣告好的array[a][b]跟 雙pointer  int ** array; 好像是不一樣的

(為什麼呢XD）

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

{

int *A= *(int **)a;

int *B= *(int **)b;

return A[0]-B[0];

}

int maxWidthOfVerticalArea(int** points, int pointsSize, int* pointsColSize){

qsort((void *)points, pointsSize, sizeof(points[0]), comp);

int diff=0;

for (int i=1;i<pointsSize;i++)

if (points[i][0]-points[i-1][0]>diff)

diff = points[i][0]-points[i-1][0];

return diff;

}