ExamPreparationIntroToProgramming

functions.h

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

void Revert( char *arr )
{
    int length = strlen(arr);

    for(int i=0; i<length; i++)
    {
        if(arr[i]>='A' && arr[i]<='Z')
        {

            arr[i]+=32;
        }
        else if(arr[i]>='a' && arr[i]<='z')
        {

            arr[i]-=32;
        }
    }
}


void Revert2( char *arr )
{
    int length = strlen(arr);

    for(int i=0; i<length; i++)
    {
        bool isCapital = arr[i]>='A' && arr[i]<='Z';
        bool isLowercase = arr[i]>='a' && arr[i]<='z';
        arr[i] +=
            isCapital * 32 +
            isLowercase * (-32);
    }
}
bool isDigit(char symbol){
    return (symbol >='0' && symbol<='9');
}

bool CheckDate(char *arr){
   int length=strlen(arr);
   if(length!=5){
    return false;
   }
   if(!isDigit(arr[0]) || !isDigit(arr[1])){
        return false;
   }
   if(arr[2]!='.'){
    return false;
   }
   if(!isDigit(arr[3]) || !isDigit(arr[4])){
    return false;
   }
   int days=(arr[0]-'0')*10 +arr[1]-'0';
   int months=((arr[3]-'0')*10 +arr[4]-'0');
   if(months<1 || months>12 ){
       return false;
   }
   switch (months){
       case 1: return (days<=31);
       case 2: return (days<=29);
       case 3: return (days<=31);
       case 4: return (days<=30);
       case 5: return (days<=31);
       case 6: return (days<=30);
       case 7: return (days<=31);
       case 8: return (days<=31);
       case 9: return (days<=30);
       case 10: return (days<=31);
       case 11: return (days<=30);
       case 12: return (days<=31);
   }
}



bool CheckDate2(char *arr){
   int length=strlen(arr);
   if(length!=5){
    return false;
   }
   if(!isDigit(arr[0]) || !isDigit(arr[1])){
        return false;
   }
   if(arr[2]!='.'){
    return false;
   }
   if(!isDigit(arr[3]) || !isDigit(arr[4])){
    return false;
   }
   int days=(arr[0]-'0')*10 +arr[1]-'0';
   int months=((arr[3]-'0')*10 +arr[4]-'0');
   if(months<1 || months>12 ){
       return false;
   }
   int maxDaysPerMonth[] =
   {
       0,
       31, 29, 31, 30, 31, 30,
       31, 31, 30, 31, 30, 31
   };
   return days <= maxDaysPerMonth[months];
}

int SumElementsOverPrimaryDiagonal(int* matrix,
                                   int n)
{
    int sum = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (i < j)
            {
                sum += matrix[i*n + j];
            }
        }
    }
    return sum;
}

int SumElementsOverPrimaryDiagonal2(int** matrix,
                                   int n)
{
    int sum = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (i < j)
            {
                sum += matrix[i][j];
            }
        }
    }
    return sum;
}

main.cpp

#include "functions.h"

int main()
{
    /*
    char arr[]=" AbAbCgH" ;
    Revert(arr);
    cout<<arr;
    */
    /*
    char arr[]="16.01";
    cout<<CheckDate2(arr);
    char arr2[]="36.02";
    cout<<endl;
    cout<<CheckDate2(arr2);
    */
    /*
    int n;
    cin >> n;
    int* matrix = new int[n * n];

    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            cin >> matrix[i*n + j];
        }
    }

    cout << SumElementsOverPrimaryDiagonal(matrix, n);
    delete[] matrix;
    */

    int n;
    cin >> n;
    int** matrix = new int*[n];

    for (int i = 0; i < n; i++)
    {
        matrix[i] = new int[n];
    }

    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            cin >> matrix[i][j];
        }
    }

    cout << SumElementsOverPrimaryDiagonal(matrix, n);

    for (int i = 0; i < n; i++)
    {
        delete[] matrix[i];
    }
    delete[] matrix;

    return 0;
}