题解 | 向量叉乘

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 计算出这两个向量叉乘的结果
 * @param vector1 int整型一维数组 
 * @param vector1Len int vector1数组长度
 * @param vector2 int整型一维数组 
 * @param vector2Len int vector2数组长度
 * @return int整型一维数组
 * @return int* returnSize 返回数组行数
 */
int* crossTimes(int* vector1, int vector1Len, int* vector2, int vector2Len, int* returnSize ) {
    // write code here
    if(vector1 == NULL || vector2 == NULL || vector1Len != 3 || vector2Len != 3)
    {
        *returnSize = 0;
        return NULL;
    }

    int *crossResult = (int *)malloc(sizeof(int) * 3);
    if(crossResult == NULL)
    {
        *returnSize = 0;
        return 0;
    }

    crossResult[0] = vector1[1] * vector2[2] - vector1[2] * vector2[1]; 
    crossResult[1] = - (vector1[0] * vector2[2] - vector1[2] * vector2[0]);
    crossResult[2] = vector1[0] * vector2[1] - vector1[1] * vector2[0];

    *returnSize = 3;

    return crossResult;
}