The introduction to the C + + algorithm race Classic PAGE16 exercise 1-3 continuous and

Title: Input positive integer n, output 1+2+3+...+n value. Tip: The goal is to solve the problem rather than practice programming

In order to output 1+2+3+...+n, you can use the first item plus the last item multiplied by the number of items divided by the 2 formula

(1) Declares the 1+2+3+...+n and M, the positive integer n of the input:

int m,n; //

(2): Enter N:

scanf ("%d", &n);

(3) Use the formula to calculate the value of M:

M= (1+n) *n/2; //

(4) Output m:

printf ("%d", M);

Full code:

//P16 Exercise 1-3 Continuous and//Purpose: Output 1+2+3+4+...+n#include <cstdio>intM,n;//m: Temp variable N: positive integer enteredintMain () {scanf ("%d",&N); M=(1+n) *n/2;//The first item plus the last item multiplied by the number of items divided by 2printf ("%d", M); return 0;}

The introduction to the C + + algorithm race Classic PAGE16 exercise 1-3 continuous and