Question

Title

Algorithms

Functional Requirements and Marks

using c++

Write a pseudo-code algorithm for the following problems:

Detect if three angles can make a triangle.    (1)

Hint: In a triangle, the sum of all angles is 180.

Switch the value of two numbers     (1)

If a=2 and b=5, we want to have a=5 and b=2 at the end.

Remember that a=b will result in the old value to of a to get lost.

Receive a set of numbers and find the max.    (1)

In the previous case (3), switch the value of first number with the max    (1)

Use what you did in (4) and sort the set of numbers.    (1)

Max value goes to the first data, then max of remaining values goes to the second, etc.

Implementation Requirements

Start each algorithm with a list of data items it uses.

In your algorithm show where each data item get its value (input from user, read from database, etc)

Use comments and description if necessary, to explain what your algorithm does.

Answer 1

Note: Done accordingly. Please comment for further help. Please uprate.

Code:

// DifferentAlgorithms.cpp : Defines the entry point for the console application.
//
#include<iostream>
using namespace std;

//checking valid traingle
/* Count how many angles given will summing them up.
If you weren't given just three angles or if they don't all add up to 180, then it cannot make up a triangle.
*/
void validTriangle(){
   int angle1,angle2,angle3,sum;
   cout<<"Please give angles :\n";
   cin>>angle1;
   cin>>angle2;
   cin>>angle3;
   sum=angle1+angle2+angle3;
   if(sum==180 && angle1>0 && angle2>0 && angle3>0){
   cout<<"Triangle is valid.\n";
   }else{
       cout<<"Triangle is invalid.\n";
   }
}

/* first adding to get sum
then subtract second from sum so we get first.
subtract first from sum so we get second*/
void switchTwoNumbers(int &first,int &second){
   first=first+second;
   second=first-second;
   first=first-second;
}

/*
set variable highest equal to the first element in the array.
walk the array starting with the 2nd element.
If an entry is higher than highest, set highest to the value
*/
int findMax(int list[],int start,int size){
   int max=list[start];
   for(int i=start;i<size;i++){
       if(max<list[i]){
       max=list[i];
       }
   }
   return max;
}

int getMaxIndex(int list[],int start,int size){
   int index=start;
   int max=list[index];
   for(int i=start;i<size;i++){
       if(max<list[i]){
       index=i;
       max=list[i];
       }
   }
   return index;
}

/* walk array starting with the 2nd element. if an entry is higher than array[0] use the swap in #2 to switch them*/
void setFirstAsMax(int list[],int size){
   int index=getMaxIndex(list,0,size);
   switchTwoNumbers(list[0],list[index]);
}

/* looping through array and swapping highest index with current index*/
void sort(int list[],int size){
   int index;
   for(int i=0;i<size;i++){
       index=getMaxIndex(list,i,size);
       if(index!=i)
       switchTwoNumbers(list[i],list[index]);
   }
}

/* Taking input from console*/
void main(){
   cout<<"1) Testing Valid Triangle:\n";
   validTriangle();
   /* Swapping two number */
   cout<<"\n2) Swapping Numbers:\n";
   int first,second;
   cout<<"Please give two numbers.\n";
   cin>>first;
   cin>>second;
   cout<<"Numbers before swapping : First "<<first<<"\tSecond "<<second<<endl;
   switchTwoNumbers(first,second);
   cout<<"Numbers after swapping : First "<<first<<"\tSecond "<<second<<endl;

   /* Finding Max */
   cout<<"3) Finding Max:\n";
   int list[10];
   cout<<"Please give 10 numbers\n";
   for(int i=0;i<10;i++){
       cin>>list[i];
   }
   int max = findMax(list,0,10);
   cout<<"Maximum Value is :"<<max<<endl;

   /* Setting First As Max */
   setFirstAsMax(list,10);
   cout<<"List after swapping with max:"<<endl;
   for(int i=0;i<10;i++){
       cout<<list[i]<<endl;
   }

   /* Sorting using Max */
   sort(list,10);

   cout<<"List after sorting:"<<endl;
   for(int i=0;i<10;i++){
       cout<<list[i]<<endl;
   }
   system("pause");
}

Output: