Logic used is simple if a triplet x,y,z occurs such that x>y<z then give the length of the array to m and continue and it gives right output in all the test cases I can think of
#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
int t;
cin>>t;
while(t--)
{
int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++)
{
cin>>a[i];
}
int l=0;
int m=0;
for(int i=0;i<n;i++)
{
l++;
if(i>0&&i<n-1)
{
if(a[i]<a[i-1]&&a[i]<a[i+1])
{
l=1;
}
}
if(m<l)
m=l;
}
if(m)
cout<<m<<endl;
else
cout<<l<<endl;
}
return 0;
}
I am trying to implement quick sort to sort a sequence of integers.
I am getting a segmentation default with the following code:
I implemented partition and quick sort recursive calls.But for some c++ reason I am getting an access to memory or an infinite loop I cant understand why.
#include <fstream>
#include<vector>
#include<iostream>
using namespace std;
int pivotSelection(vector<int> A){
return 0;
}
int partition(vector<int> &A,int l,int r){
int i=l+1;
int p = A[l];
for(int j=0; j< A.size(); j++) {
if(A[j]<p){
swap(A[j], A[i] );
i=i+1;
}
}
swap(A[l], A[i-1]);
return i;
}
vector<int> readArray(char* file){
ifstream inFile;
vector<int> A;
inFile.open(file);
int x;
while (inFile >>x ) {
A.push_back(x);
}
return A;
}
void quickSort(vector<int> &A, int l,int r){
if(r==1) {
return ;
}
if(r>l){
int p= partition(A,l,r);
quickSort(A,l,p-1);
quickSort(A,p+1,r);
}
}
int main(){
vector<int> A;//= readArray((char*)"/home/brunoeducsantos/AlgorithmFoundation/quicksort/data.txt");
A.push_back(3);
A.push_back(5);
A.push_back(7);
A.push_back(1);
int length = A.size();
quickSort(A,0,length-1);
for(int i=0;i<length;i++) cout<<A[i]<<endl;
return 0;
};
The expected result is: 1 3 5 7
Fixes noted in comments:
int partition(vector<int> &A,int l,int r){
int i=l+1;
int p = A[l];
for(int j=i; j<=r; j++) { // fix
if(A[j]<p){
swap(A[j], A[i] );
i=i+1;
}
}
swap(A[l], A[i-1]);
return i-1; // fix
}
I want to determine the intersection of 2 bi-dimensional arrays.
Here is my code:
#include < iostream >
using namespace std;
void type(int mat[][10],int n)
{
for(int i=0;i<n;i++)
for(int j=0;j<n;j++)
cin>>mat[i][j];
}
void inter(int a[][10], int n,int b[][10],int m)
{
int k1=0,p, x,ok,j, c[50],i;
for(i=0;i<n;i++){
for(j=0;j<n;j++){
p=0; x=0;
while(p<m)
{
ok=0;
while(x<m)
{
if(a[i][j]==b[p][x]) ok=1;
if(ok) c[k1++]=a[i][j];
x++;
}
p++;
}
for(i=0;i<n;i++)
{
cout<<c[i]<<" ";
cout<<endl;}
}
}
}
} // !!! added in edit!!!
int main()
{
int n,m,mat[10][10],c[30],mat2[10][10];
cout<<"n= ";cin>>n;
type(mat,n);
cout<<"m= "; cin>>m;
type(mat2,m);
inter(mat,n,mat2,m);
return 0;
}
It doesn't show me the expected answer. It shoes me numbers like these : 1
4758024
1
4758024
Can somebody help me?
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.
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!