I have never noticed that

Showing us the error might help us further assist you though

include <stdio.h> #include <stdlib.h> int main() { int integer,i, min; printf("Enter expected limit of numbers:\n "); scanf("%d", &integer); for(i=0; i<integer; i++) { printf("Enter integer %d: ",i+1); scanf("%d", &arr[i]); } min=arr[0]; for(i=0; i<integer; i+) { if(min>arr[i]) { min=arr[i]; } printf("\nSmallest integer is: %d",min); return 0; }

include <stdio.h> #include <stdlib.h> int main() { int integer,i, min; printf("Enter expected limit of numbers:\n "); scanf("%d", &integer); for(i=0; i<integer; i++) { printf("Enter integer %d: ",i+1); scanf("%d", &arr[i]); } min=arr[0]; for(i=0; i<integer; i+) { if(min>arr[i]) { min=arr[i]; } printf("\nSmallest integer is: %d",min); return 0; }

Where am I wrong?

C:\Users\user\AppData\Local\Temp\ccaVbb9v.o TM.cpp:(.text+0x3e1): undefined reference to `addition(int (*) [10], int (*) [10], int, int, int, int)' C:\Users\user\AppData\Local\Temp\ccaVbb9v.o TM.cpp:(.text+0x41d): undefined reference to `subtraction(int (*) [10], int (*) [10], int, int, int, int)' C:\Users\user\AppData\Local\Temp\ccaVbb9v.o TM.cpp:(.text+0x459): undefined reference to `multiplication(int (*) [10], int (*) [10], int, int, int, int)' C:\Users\user\Documents\collect2.exe [Error] ld returned 1 exit status

Enter expected limit of numbers: 7 Enter integer 1: 99 Enter integer 2: 78 Enter integer 3: 59 Enter integer 4: 48 Enter integer 5: 94 Enter integer 6: -100 Enter integer 7: 100 Smallest integer is: -100 [Process completed - press Enter]

C:\Users\user\AppData\Local\Temp\ccaVbb9v.o TM.cpp:(.text+0x3e1): undefined reference to `addition(int (*) [10], int (*) [10], int, int, int, int)' C:\Users\user\AppData\Local\Temp\ccaVbb9v.o TM.cpp:(.text+0x41d): undefined reference to `subtraction(int (*) [10], int (*) [10], int, int, int, int)' C:\Users\user\AppData\Local\Temp\ccaVbb9v.o TM.cpp:(.text+0x459): undefined reference to `multiplication(int (*) [10], int (*) [10], int, int, int, int)' C:\Users\user\Documents\collect2.exe [Error] ld returned 1 exit status

That's a linker error, it means that you have declaration of a function but don't have a definition for it (that may be caused by having a typo in the name, or different arguments on your declararion and definition)

That's a linker error, it means that you have declaration of a function but don't have a definition for it (that may be caused by having a typo in the name, or different arguments on your declararion and definition)

It has run

Can you help me to fix it? Is it possible?

You can post it here using wandbox or pastebin, but I can't guarantee that I can help :)

#include <iostream> #include <fstream> //including operations.h headerfile which consists addition,subtraction and multiplication function declaration #include"operations.h" using namespace std; //main function int main() { //creating input file stream object ifstream fin; //opening matrix.dat file to read data fin.open("matrix.dat"); //if file does not exists displays no such file and terminates if(!fin) { cout<<"No such file exists"; exit(0); } //declaring m1,n1 ---number of rows and columns of matrix a //m2,n2 ----number of rows and columns of matrix b int m1,n1,m2,n2; //declaring 2D array for matrix a and matrix b int a[10][10],b[10][10]; //reading row and column of first matrix from file "matrix.dat" fin>>m1; fin>>n1; //reading matrix values from file "matrix.dat" for(int i=0;i<m1;i++) for(int j=0;j<n1;j++) fin>>a[i][j]; //reading row and column of second matrix from file "matrix.dat" fin>>m2; fin>>n2; //reading matrix values from file "matrix.dat" for(int i=0;i<m2;i++) for(int j=0;j<n2;j++) fin>>b[i][j]; //displaying matrix a and b cout<<"Matrix 1 read from file:"<<endl; for(int i=0;i<m1;i++) { for(int j=0;j<n1;j++) cout<<a[i][j]<<" "; cout<<endl; } cout<<"Matrix 2 read from file:"<<endl; for(int i=0;i<m2;i++) { for(int j=0;j<n2;j++) cout<<b[i][j]<<" "; cout<<endl; } int ch; cout<<"What operation do you want to perform?\n1. addition\n2. subtraction\n3. multiplicaiton\n"; cout<<"Enter your choice: "; cin>>ch; //You can select operation what you want to perform switch(ch) { case 1: addition(a,b,m1,n1,m2,n2); break; case 2: subtraction(a,b,m1,n1,m2,n2); break; case 3: multiplication(a,b,m1,n1,m2,n2); break; } return 0; }

I will need your help around 1:55pm Which is the next 3hours

C++ I have references to *ascending-sorted* std::vector's of typedef std::pair<K2*, V2*> IntermediatePair; where K2 implements the operator<. My current challenge is: Creating std::vector of std::vector<IntermediatePair>, where each std::vector<IntermediatePair> element contains IntermediatePair`s with identical `K2. Do you have an idea?

how to manage this insertion, etc...

What do you need a vector of vectors for?

That's part of the API

C++ I have references to *ascending-sorted* std::vector's of typedef std::pair<K2*, V2*> IntermediatePair; where K2 implements the operator<. My current challenge is: Creating std::vector of std::vector<IntermediatePair>, where each std::vector<IntermediatePair> element contains IntermediatePair`s with identical `K2. Do you have an idea?

Suppose we have these vectors: 1, 1, 2, 2, 3, 4, 4 2, 3, 5, 5 So we have to create this vector of vectors [ [4,4], [3,3], [2,2,2], [1,1] ]

It ain't a rocket science. And I've given you the algo. It's like 5 lines of code. Just code it yourself bruh. Don't make us embarrassed

So just sort then push back same elements

void ThreadContext::invokeShufflePhase() { if (thread_id_ == 0) // by convention - only thread-0 performs the shuffle phase { // std::vector<std::vector<std::pair<K2*, V2*>>> auto shuffledQueue = currentJobContext_.getShuffledQueue(); for (size_t i = 0; i < currentJobContext_.getNumOfThreads(); ++i) { // here we access all threads' intermediate vectors // std::vector<std::pair<K2*, V2*>> sorted by K2 auto currIntermediateVec = currentJobContext_.getThreadContext(i).getIntermediateVec(); // here we want to insert to shuffledQueue elements of type // std::vector<std::pair<K2*, V2*>> whose K2 is identical } } // else => you aren't thread-0, so go wait on barrier }

You push into the vector from multiple threads?

This function is executed by only one thread.

void ThreadContext::invokeShufflePhase() { if (thread_id_ == 0) // by convention - only thread-0 performs the shuffle phase { // std::vector<std::vector<std::pair<K2*, V2*>>> auto shuffledQueue = currentJobContext_.getShuffledQueue(); for (size_t i = 0; i < currentJobContext_.getNumOfThreads(); ++i) { // here we access all threads' intermediate vectors // std::vector<std::pair<K2*, V2*>> sorted by K2 auto currIntermediateVec = currentJobContext_.getThreadContext(i).getIntermediateVec(); // here we want to insert to shuffledQueue elements of type // std::vector<std::pair<K2*, V2*>> whose K2 is identical } } // else => you aren't thread-0, so go wait on barrier }

#include <iostream> #include <fstream> //including operations.h headerfile which consists addition,subtraction and multiplication function declaration #include"operations.h" using namespace std; //main function int main() { //creating input file stream object ifstream fin; //opening matrix.dat file to read data fin.open("matrix.dat"); //if file does not exists displays no such file and terminates if(!fin) { cout<<"No such file exists"; exit(0); } //declaring m1,n1 ---number of rows and columns of matrix a //m2,n2 ----number of rows and columns of matrix b int m1,n1,m2,n2; //declaring 2D array for matrix a and matrix b int a[10][10],b[10][10]; //reading row and column of first matrix from file "matrix.dat" fin>>m1; fin>>n1; //reading matrix values from file "matrix.dat" for(int i=0;i<m1;i++) for(int j=0;j<n1;j++) fin>>a[i][j]; //reading row and column of second matrix from file "matrix.dat" fin>>m2; fin>>n2; //reading matrix values from file "matrix.dat" for(int i=0;i<m2;i++) for(int j=0;j<n2;j++) fin>>b[i][j]; //displaying matrix a and b cout<<"Matrix 1 read from file:"<<endl; for(int i=0;i<m1;i++) { for(int j=0;j<n1;j++) cout<<a[i][j]<<" "; cout<<endl; } cout<<"Matrix 2 read from file:"<<endl; for(int i=0;i<m2;i++) { for(int j=0;j<n2;j++) cout<<b[i][j]<<" "; cout<<endl; } int ch; cout<<"What operation do you want to perform?\n1. addition\n2. subtraction\n3. multiplicaiton\n"; cout<<"Enter your choice: "; cin>>ch; //You can select operation what you want to perform switch(ch) { case 1: addition(a,b,m1,n1,m2,n2); break; case 2: subtraction(a,b,m1,n1,m2,n2); break; case 3: multiplication(a,b,m1,n1,m2,n2); break; } return 0; }

#include <iostream> #include <fstream> //including operations.h headerfile which consists addition,subtraction and multiplication function declaration #include"operations.h" using namespace std; //main function int main() { //creating input file stream object ifstream fin; //opening matrix.dat file to read data fin.open("matrix.dat"); //if file does not exists displays no such file and terminates if(!fin) { cout<<"No such file exists"; exit(0); } //declaring m1,n1 ---number of rows and columns of matrix a //m2,n2 ----number of rows and columns of matrix b int m1,n1,m2,n2; //declaring 2D array for matrix a and matrix b int a[10][10],b[10][10]; //reading row and column of first matrix from file "matrix.dat" fin>>m1; fin>>n1; //reading matrix values from file "matrix.dat" for(int i=0;i<m1;i++) for(int j=0;j<n1;j++) fin>>a[i][j]; //reading row and column of second matrix from file "matrix.dat" fin>>m2; fin>>n2; //reading matrix values from file "matrix.dat" for(int i=0;i<m2;i++) for(int j=0;j<n2;j++) fin>>b[i][j]; //displaying matrix a and b cout<<"Matrix 1 read from file:"<<endl; for(int i=0;i<m1;i++) { for(int j=0;j<n1;j++) cout<<a[i][j]<<" "; cout<<endl; } cout<<"Matrix 2 read from file:"<<endl; for(int i=0;i<m2;i++) { for(int j=0;j<n2;j++) cout<<b[i][j]<<" "; cout<<endl; } int ch; cout<<"What operation do you want to perform?\n1. addition\n2. subtraction\n3. multiplicaiton\n"; cout<<"Enter your choice: "; cin>>ch; //You can select operation what you want to perform switch(ch) { case 1: addition(a,b,m1,n1,m2,n2); break; case 2: subtraction(a,b,m1,n1,m2,n2); break; case 3: multiplication(a,b,m1,n1,m2,n2); break; } return 0; }

This function is executed by only one thread.

#include <iostream> #include <fstream> //including operations.h headerfile which consists addition,subtraction and multiplication function declaration #include"operations.h" using namespace std; //main function int main() { //creating input file stream object ifstream fin; //opening matrix.dat file to read data fin.open("matrix.dat"); //if file does not exists displays no such file and terminates if(!fin) { cout<<"No such file exists"; exit(0); } //declaring m1,n1 ---number of rows and columns of matrix a //m2,n2 ----number of rows and columns of matrix b int m1,n1,m2,n2; //declaring 2D array for matrix a and matrix b int a[10][10],b[10][10]; //reading row and column of first matrix from file "matrix.dat" fin>>m1; fin>>n1; //reading matrix values from file "matrix.dat" for(int i=0;i<m1;i++) for(int j=0;j<n1;j++) fin>>a[i][j]; //reading row and column of second matrix from file "matrix.dat" fin>>m2; fin>>n2; //reading matrix values from file "matrix.dat" for(int i=0;i<m2;i++) for(int j=0;j<n2;j++) fin>>b[i][j]; //displaying matrix a and b cout<<"Matrix 1 read from file:"<<endl; for(int i=0;i<m1;i++) { for(int j=0;j<n1;j++) cout<<a[i][j]<<" "; cout<<endl; } cout<<"Matrix 2 read from file:"<<endl; for(int i=0;i<m2;i++) { for(int j=0;j<n2;j++) cout<<b[i][j]<<" "; cout<<endl; } int ch; cout<<"What operation do you want to perform?\n1. addition\n2. subtraction\n3. multiplicaiton\n"; cout<<"Enter your choice: "; cin>>ch; //You can select operation what you want to perform switch(ch) { case 1: addition(a,b,m1,n1,m2,n2); break; case 2: subtraction(a,b,m1,n1,m2,n2); break; case 3: multiplication(a,b,m1,n1,m2,n2); break; } return 0; }

I thought of something like: using vec = std::vector; using elem_type = pair<int, int>; // can be whatever vec<elem_type> input; std::sort(input.begin(), input.end()): vec<vec<elem_type>> vec2d; vec2d.push_back({}); const elem_type& lastval = input[0]; vec<elem_type>* current = nullptr; for(const auto& elem : input) { if(elem != lastval) { vec2d.push_back({}); current = &vec2d.back(); } current->push_back(elem); lastval = elem; }

std::pair on std C++11 (my standard required compilation) doesn't implement operator<, thus I think std::sort on that one is undefined, and I don't actually understand what you need this sort for

cppreference says otherwise

Until c++14 it wasn't constexpr

Until c++14 it wasn't constexpr

Ah okay, anyways, this line of yours: std::sort(input.begin(), input.end()): is redundant as I mentioned in comments: // std::vector<std::pair<K2*, V2*>> sorted by K2 auto currIntermediateVec = currentJobContext_.getThreadContext(i).getIntermediateVec(); That is, it's already sorted

void ThreadContext::invokeShufflePhase() { if (thread_id_ == 0) // by convention - only thread-0 performs the shuffle phase { // std::vector<std::vector<std::pair<K2*, V2*>>> auto shuffledQueue = currentJobContext_.getShuffledQueue(); for (size_t i = 0; i < currentJobContext_.getNumOfThreads(); ++i) { // here we access all threads' intermediate vectors // std::vector<std::pair<K2*, V2*>> sorted by K2 auto currIntermediateVec = currentJobContext_.getThreadContext(i).getIntermediateVec(); // here we want to insert to shuffledQueue elements of type // std::vector<std::pair<K2*, V2*>> whose K2 is identical } } // else => you aren't thread-0, so go wait on barrier }

cbook

That's not the whole code the issue is probably not here, you can use wandbox.org, it's an online compiler with multiple files support, you can copy content of your files there, press Run, then Share, then copy the URL and paste here