pow

问题 I am trying to calculate something like this: a^b mod c, where all three numbers are large. Things I've tried: Python's pow() function is taking hours and has yet to produce a result. (if someone could tell me how it's implemented that would be very helpful!) A right-to-left binary method that I implemented, with O(log e) time, would take about 30~40 hours (don't wanna wait that long). Various recursion methods are producing segmentation faults (after I changed the recursion limits) Any

问题 I have an exercise which demands a program that reverts a five digit number using pow, here is my try: #include <math.h> #include <stdio.h> void main( void ) { int number, counter = 0, last_digit, reversed = 0; printf( "Please type a five digit number and I will reverse it\n" ); scanf( "%d", &number ); for( counter = 4; counter >= 0; counter-- ) { last_digit = number % 10; number = number / 10; //printf( "%d %d %.0f %.0f\n\n", reversed, last_digit, pow ( 10, counter ), reversed + last_digit *

问题 I have an exercise which demands a program that reverts a five digit number using pow, here is my try: #include <math.h> #include <stdio.h> void main( void ) { int number, counter = 0, last_digit, reversed = 0; printf( "Please type a five digit number and I will reverse it\n" ); scanf( "%d", &number ); for( counter = 4; counter >= 0; counter-- ) { last_digit = number % 10; number = number / 10; //printf( "%d %d %.0f %.0f\n\n", reversed, last_digit, pow ( 10, counter ), reversed + last_digit *

问题 This question already has answers here : Strange behaviour of the pow function (5 answers) Closed last year . I am having some problems with pow() function in C. When ever run this code, 153 as input, the sum evaluates to 152 . However if I dont use pow() function and instead use a for loop to get the value of N n , the sum evaluates to 153 . Can anyone help please explain me this difference? #include <stdio.h> #include <string.h> #include <stdlib.h> #include <math.h> int main(void) {

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . Why does this: printf("%d\n", pow(1,0)); /* outputs 0 */ returns 0 ? I expected it to return 1 . 回答1: pow() returns a double type. You need to use %f format specifier to print a double . Using inappropriate format specifier for the supplied argument type causes undefined behaviour. Check chapter §7.21.6.1 of the

问题 While doing my homework I noticed something really strange that I just can't figure out why. int x = 5; cout << pow(x, 2); The result is 25. That's fine. But if I write the same program like this: int x = 5; int y = pow(x, 2); cout << y; The result is 24! When x is 2, 3, 4, 6, 7, 8 no problem, but with 5, 10, 11, 13 etc. result is 1 lower than it should be. Same thing with if(). for (int x = 1; x <= 20 ; x++) { if (x * x == pow(x, 2)) cout << x << endl; } It prints out numbers 1, 2, 3, 4, 6,

问题 I'm learning swift recently, but I have a basic problem that can't find an answer I want to get something like var a:Int = 3 var b:Int = 3 println( pow(a,b) ) // 27 but the pow function can work with double number only, it doesn't work with integer, and I can't even cast the int to double by something like Double(a) or a.double()... Why it doesn't supply the power of integer? it will definitely return an integer without ambiguity ! and Why I can't cast a integer to a double? it just change 3

问题 I'm learning swift recently, but I have a basic problem that can't find an answer I want to get something like var a:Int = 3 var b:Int = 3 println( pow(a,b) ) // 27 but the pow function can work with double number only, it doesn't work with integer, and I can't even cast the int to double by something like Double(a) or a.double()... Why it doesn't supply the power of integer? it will definitely return an integer without ambiguity ! and Why I can't cast a integer to a double? it just change 3

问题 And no, this does not (to my understanding) involve integer division or floating-point rounding issues. My exact code is: static void Main(string[] args) { double power = (double)1.0 / (double)7.0; double expBase = -128.0; System.Console.WriteLine("sanity check: expected: -128 ^ 0.142857142857143 = -2. actual: " + expBase + " ^ " + power + " = " + Math.Pow(expBase, power)); System.Console.ReadLine(); } The output is: sanity check: expected: -128 ^ 0.142857142857143 = -2. actual: -128 ^ 0

问题 And no, this does not (to my understanding) involve integer division or floating-point rounding issues. My exact code is: static void Main(string[] args) { double power = (double)1.0 / (double)7.0; double expBase = -128.0; System.Console.WriteLine("sanity check: expected: -128 ^ 0.142857142857143 = -2. actual: " + expBase + " ^ " + power + " = " + Math.Pow(expBase, power)); System.Console.ReadLine(); } The output is: sanity check: expected: -128 ^ 0.142857142857143 = -2. actual: -128 ^ 0