string.cpp

#include <bits/stdc++.h>

using std::cout;
using std::endl;
using std::cin;
using std::string;

int main()
{
    // length of string
    const char * name ="Singh 03-conditionals-loops";     // read only we can't write them
    int i=0;
    // name.touppercase();
    while(name[i]!='\0'){
        i++;
    }
    cout<<"Length of string is: "<<i<<endl;

    // copy string
    const char * source ="Hello, World!";
    char destination[50];
    i=0;
    while(source[i]!='\0'){
        destination[i]=source[i];
        i++;
    }
    destination[i]='\0'; // null character at end of string if we don't add it garbage values will be printed and will be treated as part of string
    cout<<"Copied string is: "<<destination<<endl;
    cout<<typeid(destination).name()<<endl; //A50_c means array of 50 characters

    // toUpperCase
    int len=i;
    for (int i = 0; i < len; i++)
    {
        if(destination[i]>='a' && destination[i]<='z'){
            destination[i]-=32;
        }
    }

    for (int i = 0; i < len; i++)
    {
        cout<<destination[i];
    }
    cout<<endl;
    //toLowerCase

    len=i;
    for (int i = 0; i < len; i++)
    {
        if(destination[i]<='Z' && destination[i]>='A'){
            destination[i]+=32;
        }
    }

    for (int i = 0; i < len; i++)
    {
        cout<<destination[i];
    }
    cout<<endl;

    // counting vowel and consonents in a string called destination

    i=0;
    int vowel=0;
    int consonet=0;
    while (i<len)
    {
        if (destination[i]>=97 and destination[i]<=122)
        {
           if(destination[i]=='a'||destination[i]=='e'||destination[i]=='i'||destination[i]=='o'||destination[i]=='u')
                    vowel++;
            else
               consonet++;
        }

        if (destination[i]>=65 and destination[i]<=90)
        {

           if(destination[i]=='a'-32||destination[i]=='e'-32||destination[i]=='i'-32||destination[i]=='o'-32||destination[i]=='u'-32)
                    vowel++;
            else
               consonet++;
        }

        i++;

    }

    cout<<destination<<" having length: "<<len<<endl;

    cout<<"vowel:"<<vowel<<" and "<<"consonents: "<<consonet<<endl;

    // valid String

    for (int i = 0; i < len; i++)
    {
        if((destination[i]>=65 && destination[i]<=90 )||(destination[i]>=65+32 && destination[i]<=90+32))
            cout<<destination[i]<<" :Valid String"<<endl;

        else
            cout<<destination[i]<<" :InValid String"<<endl;

    }


    //reverse a String

    i=0;
    int j=len-1;
    char temp;
    while (j>i)
    {
        temp=destination[i];
        destination[i]=destination[j];
        destination[j]=temp;
        i++;
        j--;
    }
    cout<<"Reversed: ";
    cout<<destination<<endl;

    i=0;
    j=len-1;
    while (j>i)
    {

        temp=destination[i];
        destination[i]=destination[j];
        destination[j]=temp;
        i++;
        j--;
    }
    cout<<destination<<endl;

    // palindrom or not
    // 
    string word="madan"; // or level
    i=0;
    j= word.length()-1;
    int pal;
    while (j>i)
    {
        if(word[i]!=word[j]){
            pal=1;
            break;
        }

        else {
            pal=0;
        }
        i++;
        j--;

    }
    if(pal==1){
        cout<<"its nota palindrome."<<endl;
    }
    else {
    cout<<"its a palindrome."<<endl;
    }
    
    // finding duplicates
    // 1. compare with other
    // 2. using hash table
    // 3. using bits
    // 
    pal=0;
    cout<<word<<endl;
    for (int i=0; i<word.length(); i++) {
        for (int j=i+1; j<word.length(); j++) {
            
            if(word[i]==word[j]){
                pal=1;
                break;
            
            }
        }
    }
    
    if(pal==0){
        cout<<"NO duplicates"<<endl;
    }
    else {
        cout<<"Having Duplicates"<<endl;
    }
    
    // another method
    int freq[26] = {0};   // for all ASCII characters
    pal = 0;
    
    for (int i = 0; i < word.length(); i++) {
        freq[word[i]-97]++;
    
        if (freq[word[i]-97] > 1) {
            pal = 1;
            break;
        }
    }
    cout << (pal==1 ? "Having Duplicates" : "NO duplicates") << endl;

    // By bit manipulation

    //Anagram Check
    string a="verbose";
    string b="observe";
    int freqq[26]={0};

    for (int i = 0; i < a.length()-1; i++)
    {
        freqq[a[i]-97]++;
        freqq[b[i]-97]--; 
    }
    int p=0;
    // for (int i = 0; i < 26; i++)
    // {
    //     cout<<freqq[i]<<"  ";
    // }
    
    if(a.length()==b.length()){
    for (int i = 0; i < 26; i++)
    {
        if((freqq[i]!=0)){
            p=1;
            break;
        }
        
    }
}

    if (p==1)
    {
        cout<<a<<" and "<<b<<" are Non-Anagram"<<endl;
    }
    else
    {
        cout<<a<<" and "<<b<<" are Anagram"<<endl;

    }
    
    // permutation of string
    
    

    
    return 0;
}