输出 n 层的倒三角形

void printTriangle(int32_t layerNum)
{
    if (layerNum < 1){
        return;
    }
    
    auto printSpaces = [](int32_t num)
    {
        for (int32_t i = 0; i != num; ++i){
            printf(" ");
        }
    };
    
    auto printSatrs = [](int32_t num)
    {
        for (int32_t i = 0; i != num; ++i){
            printf("*");
        }
        printf("\n");
    };
    
    for (int32_t currentNum = layerNum - 1, spaceWide  = 0;
         currentNum != -1;
         ++spaceWide, --currentNum){
        printSpaces(spaceWide);
        printSatrs(currentNum * 2 + 1);
    }
}