Beg 1+2+3+...+n

Title Description:

Ask for 1+2+3+...+n, the request cannot use multiplication method, for, while, if, else, switch, case and other keywords and conditional judgment statement (A? B:C).

Input:

The input may contain multiple test samples.
For each test case, the input is an integer n (1<= n<=100000).

Output:

corresponding to each test case,
The value of the output 1+2+3+...+n.

Sample Input:

3
5

Sample output:

6
15

AC Code:

#include <stdio.h>
 
int Add (int n, int *p) {
    n && Add (n-1, p);
 
    return (*p + = n);
}
 
int main () {
    int n;
    while (scanf ("%d", &n)! = EOF) {
        int sum = 0;
        Add (n, &sum);
        printf ("%d\n", sum);
    }
 
    return 0;
}
 
/**************************************************************
    problem:1506
    user:wusuopubupt
    Language:c
    result:accepted
    time:630 Ms
    memory:1212 KB
************************************** **************************/