Basically this is my code and it works fine. I just don't know how to print it in descending order. This code basically shows the odd numbers:1,3,5,7. I want it to be printed 7,5,3,1. I know I need use the sort function but I dont know how.
#include <iostream>
using namespace std;
void fillArray(int arr[], int &n);
void printArray(int arr[], int n);
void findSum(int arr[], int &n);
int main()
{
int n;
cin>>n;
int arr[n];
fillArray(arr,n);
printArray(arr,n);
findSum(arr,n);
return 0;
}
void fillArray(int arr[], int &n)
{
int j=1;
for(int i=0;i<n;i++)
{
if(j%2==1)
arr[i]=j;
else
i--;
j++;
}
}
void printArray(int arr[], int n)
{
for(int i=0;i<n;i++)
{
cout<<arr[i]<<", ";
}
}
void findSum(int arr[], int &n)
{
int sum=0;
for(int i=0;i<n;i++)
{
sum=sum+arr[i];
}
}
for(int i = n-1; i >= 0; i--)
{
cout << arr[i] << ", ";
}
example:
void printArray(int *tab, int size)
{
for (int i = size - 1; i >= 0; i--)
std::cout << tab[i] << std::endl;
}
int main() {
int tab[3] = { 1,2,3 };
printArray(tab, 3);
}
You should begin from last element array, and decrement iterator (i) to i == 0
You can simply use a sort function. There is one included with the algorithm header.
#include <algorithm> // this goes at the top
void printArray(int arr[], int n)
{
sort(arr, arr+n, [](int x, int y){return y<x;});
for(int i=0;i<n;i++)
cout << arr[i] << endl;
}
the [](int x, int y){return y<x;} part is just to make it descending. Normally it is y>x, at which point you can just omit the third parameter
Here is a repl:
https://repl.it/JQor/0
I am trying to implement min-heap just by reversing the propeties of max_heapify int the code but I am getting a segmentation fault(core dumped) during execution.What I know somewhere the code is accessing a memory to which it does not has access to. What is the problem with this code?
#include <iostream>
using namespace std;
void min_heapify(int a[], int i, int n)
{
int l,r,smallest,loc;
l=(2*i);
r=(2*i+1);
if((l<=n) && (a[l]>a[i]))
smallest=i;
else
smallest=l;
if((r<=n) && (a[smallest]>a[r]))
smallest=r;
if(smallest != i)
{
loc=a[i];
a[i]=a[smallest];
a[smallest]=loc;
min_heapify(a,smallest,n);
}
}
void build_min_heap(int a[], int n)
{
for(int k=n/2;k>=1;k--)
{
min_heapify(a,k,n);
}
}
void heapsort(int a[], int n)
{
build_min_heap(a,n);
int temp,i;
for(i=n;i>=2;i--)
{
temp=a[i];
a[i]=a[1];
a[1]=temp;
min_heapify(a,1,i-1);
}
}
main()
{
cout<<"Enter the number of elements\n";
int n;
cin>>n;
cout<<"Enter the numbers\n";
int a[n];
for(int i=1;i<=n;i++)
cin>>a[i];
heapsort(a,n);
cout<<"::::::::::::::::The Sorted List Is::::::::::::::\n";
for(int i=1;i<=n;i++)
cout<<a[i]<<endl;
return 0;
}
I know the logic how to merge two arrays but the problem is how to code.
This was my code n it is giving correct ans but my sir told me that do it again,please tell me what I have to add in this code,
#include<iostream>
using namespace std;
int mergeArrays(int array1[],int size1,int array2[],int size2);
int main()
{
const int size1=8;
const int size=12;
int arrayA[size1]={10,25,37,49,50,51,55,60};
int arrayB[size]={2,5,26,27,29,32,40,45,70,80,90,95};
mergeArrays(arrayA,size1,arrayB,size);
}
int mergeArrays(int array1[],int size1,int array2[],int size2)
{
int size3=size1+size2;
int *array3=new int[size3];
int k=0;
for(int i=0;i<size1;i++)
{
array3[k]=array1[i];
cout<<" "<<array3[k];
}
int j=0;
for(int i=size1;i<size2;i++)
{
array3[k]=array2[j];
}
for(int i=size1;i<size2;i++)
{
for(int j=0;j<size2;j++)
{
array3[i]=array2[j];
cout<<" "<<array3[i];
}
cout<<endl;
delete[]array3;
return array3[k++];
}
}
I had searched this in many places but could not corrected my code
I had written this code but it is not giving correct ans.
#include<iostream>
using namespace std;
int merge(int *a,int *b,int aSize,int bSize);
int main()
{
const int aSize={8};
const int bSize={12};
int arrayA[aSize]={10,25,37,49,50,51,55,60};
int arrayB[bSize]={2,5,26,27,29,32,40,45,70,80,90,95};
merge(arrayA,arrayB,aSize,bSize);
return 0;
}
int merge(int *a,int *b,int aSize ,int bSize)
{
int cSize=aSize+bSize;
int *c=new int[cSize];
int j=0,k=0;
int i=0;
while(i<=aSize&&j<=bSize )
{
if(a[aSize ]<=b[bSize])
{
c[k]=a[aSize];
k++;
i++;
}
else
{
c[k]=b[bSize];
k++;
j++;
}
}
for(int i=0;i<k;i++)
{
cout<<c[i]<<endl;
}
delete[]c;
return c[k++];
}
your sir request you do Merging two arrays in ascending order. so i think you should return a new array, fill with array1 and array2's element, and the elements should be ascending order. here is a implement.(suppose your input arraies is already in ascending order.)
#include <iostream>
using namespace std;
int mergeArrays(int array1[],int size1,int array2[],int size2, int outArray[]);
int main()
{
const int size1=8;
const int size=12;
int arrayA[size1]={10,25,37,49,50,51,55,60};
int arrayB[size]={2,5,26,27,29,32,40,45,70,80,90,95};
int outArray[size1+size];
int len = mergeArrays(arrayA,size1,arrayB,size, outArray);
cout <<" "<< len;
for (int i = 0; i< size1+size; ++i){
cout <<" " << outArray[i];
}
}
int mergeArrays(int array1[], int size1, int array2[], int size2, int outArray[])
{
int i=0, j=0, k=0;
int retSize = size1+size2;
while (k<retSize){
if (i==size1){// only left array2, copy it
for (; j<size2; ++j){
outArray[k++] = array2[j];
}
}else if (j == size2) { // only left array1, copy it
for (; i<size1; ++i){
outArray[k++] = array1[i];
}
}
else if (array1[i] > array2[j]){ // copy the min value to outArray
outArray[k++] = array2[j++];
}else{
outArray[k++] = array1[i++];
}
}
return k;
}
now, let's look at your first code:
int mergeArrays(int array1[],int size1,int array2[],int size2)
{
int size3=size1+size2;
int *array3=new int[size3];
int k=0;
for(int i=0;i<size1;i++)
{
array3[k]=array1[i]; // k is not changed, so you just assign array1's each value to array3[0]
cout<<" "<<array3[k];
}
int j=0;
// what's the purpose of this loop?
// and in loop, you don't use i, you just repeat set array3[0] = array2[0]!!
for(int i=size1;i<size2;i++)
{
array3[k]=array2[j];
}
for(int i=size1;i<size2;i++) // if array2's length bigger than array1's, will enter this loop.
{
for(int j=0;j<size2;j++)
{
array3[i]=array2[j]; // this just repeat assign array2's each value to array3[i]!!
cout<<" "<<array3[i];
}
cout<<endl;
delete[]array3;
return array3[k++]; // you delete array3, but at here you access it!! this will crash!
// also, in this for i loop, you have return, so it will only execute once.
}
// reach function end and no return if not enter for loop.
}
I haven't looked at your second code. I think you still need to do more study.
# include <iostream>
using namespace std;
class mm
{
private:
int k[1000];
int n;
int i;
int a;
int b;
int f;
public:
mm ()
{
a=0;
b=1;
f=0;
i=0;
for(int i=0; i<n;i++)
k[i]=0;
};
~mm()
{
}
void fib(int n)
{
for (int i=0;i<n;i++)
{
if (i<=1)
f=i;
else
{
f=a+b;
a=b;
b=f;
}
k[i]=f;
}
for (int j=0;j<n;j++)
cout<<k[j]<<" ";
}
int se (int n, int i)
{
if (n==1)
return 1;
else
return 1/k[i] + se (n-1, i+1);
}
};
int main()
{
int n;
cout<<"Enter n:";
cin>>n;
mm p;
cout<<"fib: "<<endl;
p.fib(n);
cout<<endl;
cout<<"se: ";
cout<<p.se(n,0);
return 0;
}
Recursion function from main is not responding. Maybe the array k[i] is not working, but I cant find the reason. Can anyone help me?
k[0] is set to 0. When you then call se(n,0) in main, it computes 1/k[0] + se(n-1,1) which is a division by zero.
I am using a simple approach to convert an array into heap in bottom up manner. I could not find the mistake. Can some one please have a look and let me know.
Basically I am making out of a random array in bottom up manner.
for(int i=n/2;i>=1;i--)
{
heapify(i,n,arr);
}
There is some issue with heapify procedure ,which sometimes give correct result and most of times wrong.
`#include<iostream>
#include<conio.h>
using namespace std;
int min(i
nt x,int y,int z)
{
return ((x>y?x:y)>z?(x>y?x:y):z);
}
int left(int i)
{
return (2*i);enter code here
}
int right(int i)
{
return (2*i+1);
}
int parent(int i)
{
return (i/2);
}
int heapify(int i,int n,int arr[])
{
int temp;
int l=left(i);
int r=right(i);
temp=i;
if(l<=n&&arr[l]<arr[i])
temp=l;
else if(r<=n&&arr[temp]>arr[r])
temp=r;
if(temp!=i)
{
int x=arr[temp];
arr[temp]=arr[i];
arr[i]=x;
heapify(temp,n,arr);
}
//else return 0;
}
int deletemin(int n,int arr[])
{
cout<<arr[1]<<"\ndeLeted\n";
arr[1]=arr[n];
}
int insert(int x,int size,int arr[])
{
arr[size]=x;
int i=(size);
do
{
i=parent(i);
if(arr[i]!=min(arr[i],arr[left(i)],arr[right(i)]))
heapify(i,(size),arr);
else
return 0;
}while(i!=1);
}
int main()
{
int n,t,arr[100];
cin>>t;
while(t--)
{
cin>>n;
for(int i=1;i<=n;i++)
cin>>arr[i];
for(int i=n/2;i>=1;i--)
{
heapify(i,n,arr);
}
for(int i=1;i<=n;i++)
cout<<arr[i]<<" ";
deletemin(n,arr);
n--;
heapify(1,n,arr);
for(int i=1;i<=n;i++)
cout<<arr[i]<<" ";
int y;
cout<<"what value do you want to insert\n";
cin>>y;
n++;
insert(y,n,arr);
for(int i=1;i<=n;i++)
cout<<arr[i]<<" ";
}
getch();
return 0;
}
`
One simple observation is that your min function is wrong! It doesn't return the min of 3 numbers. Do it with ifs for the moment!