#include< stdio.h >
#include < stdlib.h >
 
int
    main()
{
    float ne;
    float last;
    float number;
    printf( "输入一个数：\n");
    scanf( "%f", &number );
    if( number < 0 )
    {
        printf( "你输入有错\n");
        return EXIT_FAILURE;
    }
    ne = 1;
    do
    {
        last = ne;
        ne = ( last + number/last)/2;
        printf( "%.15e\n",ne);
    }
    while( ne!= last );
    printf( "%g的平方根为%g\n",number,ne );
    system( "pause" );
    return EXIT_FAILURE;
}