1.题目要求如图所示:

示例 1:

输入: rowIndex = 3
输出: [1,3,3,1]

示例 2:

输入: rowIndex = 0
输出: [1]

示例 3:

输入: rowIndex = 1
输出: [1,1]

先用malloc函数创造一个二维数组，变成杨辉三角，然后再用一维数组找到所指的那一行:

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* getRow(int rowIndex, int* returnSize) {
    int order = rowIndex + 1;
    int** triangle = (int**)malloc(sizeof(int*) * order);
    int i = 0;
    int l = 1;
    for(i = 0;i < order;i++)
    {
        triangle[i] = (int*)malloc(sizeof(int) * l);
        l++;
    }
    int j = 0;
    for(i = 0;i < order;i++)
    {
        for(j = 0;j <= i;j++)
        {
            if(j == 0){
                triangle[i][j] = 1;
            }else if(j == i){
                triangle[i][j] = 1;
            }else{
                triangle[i][j] = triangle[i - 1][j - 1] + triangle[i - 1][j];
            }
        }
    }
    int* number = (int*)malloc(sizeof(int) * order);
    *returnSize = order;
    int f = 0;
    j = 0;
    for(j = 0;j < order;j++)
    {
        number[f] = triangle[rowIndex][j];
        f++;
    }
    return number;
}