An algorithm to solve the numerical value of the whole number of square __ algorithm detailed

1. Description of the problem

Implementation functions:

Double power (double base,int exponent)

To find the exponent of base, do not use the library function, do not consider the problem of large numbers.

2. Solution 1

consider boundary issues;

#include <iostream> #include <string> using namespace std; #define Dbl_min 0.000001 Double power (double base, int exponent) {if (Base < Dbl_min && Base >-dbl_m
    In) {return 0.0;
    
    Double result = 1.0;
    int unsignedexponent = exponent;
    if (Exponent < 0) {unsignedexponent =-exponent;
    for (int i = 1; i < unsignedexponent. i++) {result *= base;
    } if (Exponent < 0) {result = 1.0/result;
return result;
    int main (int argc, const char * argv[]) {double base = 12.0;
    
    int exponent =-2; cout<< "base = <<base<<"; exponent = "<<exponent<<";
    
    The result is: "<<power (base, exponent) <<endl;
    base = 0.0;
    
    exponent = 2; cout<< "base = <<base<<"; exponent = "<<exponent<<";
 The result is: "<<power (base, exponent) <<endl;   
    base =-0.000000009;
    
    exponent = 12; cout<< "base = <<base<<"; exponent = "<<exponent<<";
    
    The result is: "<<power (base, exponent) <<endl;
return 0; }

2. Solution 2

Assuming that the solution 32 times, if the known 16 times, then as long as 16 square on the basis of the second time can be, and 16 square is 8 square squared, an analogy.

#include <iostream> #include <string> using namespace std; #define Dbl_min 0.000001 Double powerunsignedexponent (double base, int exponent) {if (exponent = 0) {R
    Eturn 1.0;
    } if (exponent = = 1) {return base;
    }//exponent >> 1 = exponent/2 double result = Powerunsignedexponent (base, exponent>>1);
    
    Result *= result;
    If exponent is odd if (exponent & 0x01) = = 1) {result *= base;
return result; Double power (double base, int exponent) {if (Base < Dbl_min && Base >-dbl_min) {retur
    n 0.0;
    
    Double result = 1.0;
    int unsignedexponent = exponent;
    if (Exponent < 0) {unsignedexponent =-exponent;
    
    result = Powerunsignedexponent (base, unsignedexponent);
    if (Exponent < 0) {result = 1.0/result;
return result; int main (int arGC, const char * argv[]) {double base = 12.0;
    
    int exponent =-2; cout<< "base = <<base<<"; exponent = "<<exponent<<";
    
    The result is: "<<power (base, exponent) <<endl;
    base = 0.0;
    
    exponent = 2; cout<< "base = <<base<<"; exponent = "<<exponent<<";
    
    The result is: "<<power (base, exponent) <<endl;
    base =-0.000000009;
    
    exponent = 12; cout<< "base = <<base<<"; exponent = "<<exponent<<";
    
    The result is: "<<power (base, exponent) <<endl;
return 0;
 }

reference:"sword refers to the name of an offer to be interviewed by a typical program"-Face question 11: The integer number of the value of the second party