Programming algorithm: Find 1+2+...+n (function inheritance) code (c + +)

Title: Seek 1+2+...+n, the request cannot use multiplication and division method \for\while\if\else\switch\case and so on key word and Condition judgment statement (A? B:C).

You can use function inheritance, recursive invocation, each recursive value minus 1, using the negation operation (!), that is, not 0 is 0, 0 is 1.

Code:

* * * * * main.cpp * * *  Created on:2014.7.12 * 
 This column more wonderful content: http://www.bianceng.cnhttp:// www.bianceng.cn/Programming/sjjg/
 *      author:spike 
 /
      
#include <stdio.h>  
#include < stdlib.h>  
#include <string.h>  
#include <math.h>  
      
using namespace std;  
      
Class A {public  
:  
    virtual size_t Sum (size_t N) {return  
        0;  
    }  
};  
      
A * array[2];  
      
Class B:public A {public  
:  
    virtual size_t Sum (size_t N) {return  
        array[!! N]->sum (n-1) + N;  
    }  
};  
      
int Sum (int n) {  
    a A;  
    b b;  
    Array[0] = &a;  
    ARRAY[1] = &b;  
    int value = Array[1]->sum (n);  
    return value;  
}  
      
int main (void)  
{  
    size_t result = Sum;  
    printf ("result =%d\n", result);  
    return 0;  
}

Output:

result = 55

Author: csdn Blog Caroline-wendy