Answers for "2d arrays"

2d array

int a[2][3]= {
        {1, 2, 3},
        {4, 5, 6}
    };
    
    cout << a[1][1]; // Output is 5

Index through 2d array

int[][]x;//define
for(int i=0;i<x.length;i++){
  for(int j=0;j<x[i].length;j++){
    //dp something with x[i][j]
  }
}

Index through 2d array

int[][]x;//define
for(int []y:x){
  for(int a:y){
    //do something with a
  }
}

c fill 2d array

// Either
int disp[2][4] = {
  {10, 11, 12, 13},
  {14, 15, 16, 17}
};

// Or 
int disp[2][4] = { 10, 11, 12, 13, 14, 15, 16, 17};

// OR
int i, j;
for (i = 0; i < HEIGHT; i++) { // iterate through rows
  for (j = 0; j < WIDTH; j++) { // iterate through columns
    disp[i][j] = disp[i][j];
  }
}

2d array java

int[][] arr = new int[10][20]; 
        arr[0][0] = 1;

c program to represent 2d matrix in 1d matrix

#include<stdio.h>
#define n 3
int main()
{
int a[n][n],b[n*n],c[n*n],i,j,k=0,l=0;
printf(“\n Enter elements of 2D array : “);
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
scanf(“%d”,&a[i][j]);
}
}
printf(“\n Given 2D array : \n“);
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
printf(“%d ”,a[i][j]);
}
printf(“\n”);
}
printf(“\n Row wise \n”);
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
b[k]=a[i][j];
k++;
}
}
printf(“\n Column wise \n”);
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
c[l]=a[j][i];
l++;
}
}
}