#include <bits/stdc++.h>
using namespace std;
#define V 200

int source(int shortestDist[], int visited[]) {
  int minDist = INT_MAX, index;
  for (int i = 0; i < V; i++) {
    if (visited[i] == 0 && shortestDist[i] <= minDist) {
      minDist = shortestDist[i];
      index = i;
    }
  }
  return index;
}

void dijkstra(int adj[V][V], int s) {
  int visited[V];
  int shortestDist[V];
  for (int i = 0; i < V; i++) {
    shortestDist[i] = INT_MAX;
    visited[i] = 0;
  }
  shortestDist[s] = 0;
  for (int i = 0; i < V-1; i++) {
    int w = source(shortestDist, visited);
    visited[w] = 1;
    for (int j = 0; j < V; j++) {
      if (visited[j] == 0 && adj[w][j] && shortestDist[w] != INT_MAX && shortestDist[w] + adj[w][j] < shortestDist[j]) {
        shortestDist[j] = shortestDist[w] + adj[w][j];
      }
    }
  }
  // print out all shortest distances
  /* for (int i = 0; i < V; i++) {
    cout << shortestDist[i] << endl;
  } */
  int list[10] = {7,37,59,82,99,115,133,165,188,197};
  for (int i = 0; i < 10; i++) {
    cout << shortestDist[list[i]-1] << ",";
  }
}

int main() {
  int adj[V][V] = {0};
  ifstream file("dijkstraData.txt");
  string str;
  while (getline(file, str)) {
    istringstream iss(str);
    int source;
    iss >> source;
    // cout << "source is " << source-1 << endl;
    int end, l;
    char comma;
    while ( iss >> end >> comma >> l ) {
      adj[source-1][end-1] = l;
      // cout << "end is " << end-1 << " and length is " << l << endl;
    }
  }
  
  // print out adjacency matrix
  /* for (int i = 0; i < V; i++) {
    for (int j = 0; j < V; j++) {
      cout << adj[i][j] << " ";
    }
    cout << endl;
  } */

  dijkstra(adj, 0);
}

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}