zoj 2330 A^B == B^A?

#include <cstdio>#include <cmath>#define ZERO 1e-14#define E exp(1.0f) double A;int main (){    while ( scanf ( "%lf", &A ) != EOF )    {        if ( A - E > ZERO ) printf ( "-1n" );        else        {double high, low, mid, d; high = 45, low = E; while ( high - low >= ZERO ) {     mid = ( high + low ) / 2;     d = log ( mid ) / mid - log ( A ) / A;     if ( d < ZERO && d > -ZERO )         break;     else if ( d > ZERO )     {        low = mid + 0.0000001;     }     else if ( d < -ZERO )     {         high = mid - 0.0000001;     } } printf ( "%0.5fn", mid ); d = fabs ( log ( mid ) / mid - log ( A ) / A );        }    }    return 0;}