#include using namespace std; bool isThere(string s, char c, int si, int ei){     //return true if char c is present in s at index in range [si,ei]     //return false otherwise     //you can assume 0<=si<=ei

C PROGRAMMING   Instructions: Use the code template below to implement the length() and reverse() functions into the main() /* This program will create a string which is the reverse of an original string using pointers. * Performs string handling, manipulates pointers, passes pointers to functions. */ #include <stdio.h>#include <stdlib.h> int length( ){    while(str1[len++] != '\0');   // Calculate length of string        len--;                        // Remove the null character        len--;                        // Array index start from 0 to (length -1)       return ; } void reverse( ){        while (counter < len)    {        i = str1[counter];        str1[counter] = str1[len];        str1[len] = i;        counter++;        len--;    }     return ;} int main (){    char str1[41];   // String to be Reversed     printf("Enter some text (No spaces and 40 characters max): ");    scanf("%40s", str2);     printf("Reversed string: %s\n", str1);     return 0;}

#include #include using namespace std; //function prototypesint countLetters(char*); int countDigits(char*); int countWhiteSpace(char*); int main() { int numLetters, numDigits, numWhiteSpace; char inputString[51]; cout <<"Enter a string of no more than 50 characters: " << endl << endl; cin.getline(inputString,51); numLetters = countLetters(inputString); numDigits = countDigits(inputString); numWhiteSpace = countWhiteSpace(inputString); cout << "The number of letters in the entered string is " << numLetters << endl; cout << "The number of digits in the entered string is " << numDigits << endl; cout << "The number of white spaces in the entered string is " << numWhiteSpace << endl; return 0; }   int countLetters(char *strPtr) { int occurs = 0; while(*strPtr != '\0') // loop is executed as long as// the pointer strPtr does not point // to the null character which// marks the end of the string // isalpha determines…

#include <bits/stdc++.h>using namespace std;int main() { double matrix[4][3]={{2.5,3.2,6.0},{5.5, 7.5, 12.6},{11.25, 16.85, 13.45},{8.75, 35.65, 19.45}}; cout<<"Input no in first row of matrix"<<endl; for(int i=0;i<3;i++){     double t;     cin>>t;     matrix[0][i]=t; } cout<<"Contents of the last column in matrix"<<endl; for(int i=0;i<4;i++){     cout<<matrix[i][2]<<" "; } cout<<"Content of first row and last column element in matrix is: "<<matrix[0][3]<<endl; matrix[3][2]=13.6; cout<<"Updated matrix is :"<<endl; for(int i=0;i<4;i++){     for(int j=0;j<3;j++){         cout<<matrix[i][j]<<" ";     }cout<<endl; } return 0;}   Please explain this code