開根號小數點後精度兩位數

#include <stdio.h>

unsigned int square_root_fun(unsigned int value, unsigned int *after_dec_point_ptr)

{

    unsigned int max_num, i, root;

    if (value <= 1)

    {

        if (after_dec_point_ptr != NULL)

            *after_dec_point_ptr = 0;

        return value;

    }

    value *= 10000; // Magnification 10000 times

    for (max_num = 31; max_num > 0; max_num--)

    {

        if (value & (1 << max_num))

            break;

    }

    root = 0;

    for (i = (max_num >> 1); i > 0; i--)

    {

        if (value >= ((root | (1 << i)) * (root | (1 << i))))

            root |= (1 << i);

    }

    if (i == 0)

    {

        if (value >= ((root | (1 << i)) * (root | (1 << i))))

            root |= (1 << i);

    }

    if (after_dec_point_ptr != NULL)

    {

        *after_dec_point_ptr = root % 100; // Restore magnification and Storage position after decimal point

    }

    root /= 100; // Restore magnification

    return root;

}

int main()

{

    unsigned int var_a, root, after_dec_point_ptr;

    printf("\nPlease input a value:");

    scanf("%d", &var_a);

    printf("\n=============================================\n");

    root = square_root_fun(var_a, &after_dec_point_ptr);

    printf("%d square root is %d.%d", var_a, root, after_dec_point_ptr);

    printf("\n=============================================\n");

    return 0;

}

Please input a value:123456

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123456 square root is 351.36

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Please input a value:2345

=============================================

2345 square root is 48.42

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Please input a value:1

=============================================

1 square root is 1.0

=============================================

Please input a value:0

=============================================

0 square root is 0.0

=============================================