##### Simple Array Sum

Given an array of N integers, can you find the sum of its elements?

**Input Format**

The first line contains an integer, N, denoting the size of the array.

The second line contains N space-separated integers representing the array’s elements.

**Output Format**

Print the sum of the array’s elements as a single integer.

Sample Input

6

1 2 3 4 10 11

**Sample Output**

31

Explanation

We print the sum of the array’s elements, which is: .

1+2+3+4+10+11=31

```
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
int main() {
int n,i,a,sum=0;
scanf("%d",&n);
if(n<=1000){
for(i=0;i<n;++i){
scanf("%d",&a);
sum=sum+a;
}
printf("%d",sum);
return 0;
}
}
```

Competitive coding

Hackerrank problem

###### According to cs.uic.edu

**Overview**

An array is a collection of data items, all of the same type, accessed using a common name.

A one-dimensional array is like a list; A two dimensional array is like a table; The C language places no limits on the number of dimensions in an array, though specific implementations may.

Some texts refer to one-dimensional arrays as vectors, two-dimensional arrays as matrices, and use the general term arrays when the number of dimensions is unspecified or unimportant.

**Declaring Arrays**

Array variables are declared identically to variables of their data type, except that the variable name is followed by one pair of square [ ] brackets for each dimension of the array.

Uninitialized arrays must have the dimensions of their rows, columns, etc. listed within the square brackets.

Dimensions used when declaring arrays in C must be positive integral constants or constant expressions.

In C99, dimensions must still be positive integers, but variables can be used, so long as the variable has a positive value at the time the array is declared. ( Space is allocated only once, at the time the array is declared. The array does NOT change sizes later if the variable used to declare it changes. )

**Examples:**

int i, j, intArray[ 10 ], number;

float floatArray[ 1000 ];

int tableArray[ 3 ][ 5 ]; /* 3 rows by 5 columns */

const int NROWS = 100; // ( Old code would use #define NROWS 100 )

const int NCOLS = 200; // ( Old code would use #define NCOLS 200 )

float matrix[ NROWS ][ NCOLS ];

**C99 Only Example:**

int numElements;

printf( “How big an array do you want? ” );

scanf( “%d”, &numElements; )

if( numElements <= 0 ) {
printf( "Error - Quitting\n" );
exit( 0 );
}
double data[ numElements ]; // This only works in C99, not in plain C
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