C Language Examples - Calculate the Sum of Natural Numbers
C Language ExamplesNatural numbers refer to numbers that represent the quantity of objects, that is, starting from 0, 0, 1, 2, 3, 4, ... one after another, forming an infinite collection, namely non-negative integers.
Example - Using for
#include <stdio.h>
int main()
{
int n, i, sum = 0;
printf("Enter a positive integer:");
scanf("%d",&n);
for(i=1; i <= n; ++i)
{
sum += i; // sum = sum+i;
}
printf("Sum = %d",sum);
return 0;
}
Example - Using while
#include <stdio.h>
int main()
{
int n, i, sum = 0;
printf("Enter a positive integer:");
scanf("%d",&n);
i = 1;
while ( i <=n )
{
sum += i;
++i;
}
printf("Sum = %d",sum);
return 0;
}
Run result:
输入一个正整数: 100 Sum = 5050
Example - Using Recursion
#include <stdio.h>
int addNumbers(int n);
int main()
{
int num;
printf("Enter an integer:");
scanf("%d", &num);
printf("Sum = %d",addNumbers(num));
return 0;
}
int addNumbers(int n)
{
if(n != 0)
return n + addNumbers(n-1);
else
return n;
}