【C语言】查找一组数中的最大、最小值

查找一组数中的最大、最小值

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/**
 * 查找一组数中的最大数
 * @param  nums 数组指针
 * @param  step sizeof(type)
 * @param  n    该组数中有几个数
 * @return      未找到返回-1，找到返回该数的索引
 */
int findMax(const void *nums, int step, int n)
{
    int index = -1;
    uint32_t i = 0;
    uint32_t maxVal = 0;
    uint8_t *p = (uint8_t *)nums;
    uint32_t tmp = 0;

    if(step == 1)
        maxVal = *((uint8_t *)(p));
    else if(step == 2)
        maxVal = *((uint16_t *)(p));
    else if(step == 4)
        maxVal = *((uint32_t *)(p));
    else
        return index;

    for(i = 0; i != n; i++)
    {
        if(step == 1)
            tmp = *((uint8_t *)(p + i * step));
        else if(step == 2)
            tmp = *((uint16_t *)(p + i * step));
        else if(step == 4)
            tmp = *((uint32_t *)(p + i * step));
        else
            return -1;

        if(maxVal < tmp)
        {
            maxVal = tmp;
            index = i;
        }
    }
    return index;
}

/**
 * 查找到一组数中的最小数
 * @param  nums 数组指针
 * @param  step sizeof(type)
 * @param  n    该数组有几个数
 * @return      未找到返回-1，找到返回该值索引
 */
int findMin(const void *nums, int step, int n)
{
    int index = -1;
    uint32_t i = 0;
    uint32_t minVal = 0;
    uint8_t *p = (uint8_t *)nums;
    uint32_t tmp = 0;

    if(step == 1)
        minVal = *((uint8_t *)(p));
    else if(step == 2)
        minVal = *((uint16_t *)(p));
    else if(step == 4)
        minVal = *((uint32_t *)(p));
    else
        return index;

    for(i = 0; i != n; i++)
    {
        if(step == 1)
            tmp = *((uint8_t *)(p + i * step));
        else if(step == 2)
            tmp = *((uint16_t *)(p + i * step));
        else if(step == 4)
            tmp = *((uint32_t *)(p + i * step));
        else
            return -1;

        if(minVal >= tmp)
        {
            minVal = tmp;
            index = i;
        }
    }
    return index;
}

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