CareerCup

1.Make a function to reverse the string passed:: String Reverse(String s){}
2.Reverse whole string.:: s=Reverse(s);
3.Split The String by space. a[] = s.Split(" ");
3.For each word in a, Reverse and print i.e:: a[i] = Reverse(a[i]) then print a[i].

1. Split the string by space String arr[] = str.split(" ");
2. for (i=arr.length - 1; i>=0; i--)   System.out.print(arr[i] + " ");

My solution

String [] lSplitted = s.split(" ");
		for(int i = lSplitted.length - 1; i >= 0; i-- ) {
			System.out.print(lSplitted[i] + (i>0?" ":""));

}

Hi. Here is O(n) time complexity and O(1) memory solution that is readable and small, using C++.

void reverse_print(string const &s)
{
    copy(s.rbegin(), s.rend(), ostream_iterator<char>(cout, ""));
}

public String reverse(String ss){
if(ss.length()==0)return null;
else if(ss.length()==1)return ss;
else return ss.substring(ss.length()-1)+reverse(ss.substring(0, ss.length()-1));

}

why can't this be a s simple as

split with space
push all in stack
pop all

String str = "This is test";
		String[] strArray = str.split(" ");
		String newStr= "";
		for(String s:strArray){
			newStr = s + ("".equals(newStr)?newStr:" ") + newStr ;
		}
		System.out.println(newStr);

private static String revereseWords(String inputString,char spaceChar){
		char[] charArray = inputString.toCharArray();
		int totalLength = charArray.length;
		char[] destArray = new char[totalLength];
		int spaceCount = 0;
		for (int i = totalLength , length = 0; i > 0; i--,length++) {
			if (charArray[i-1] != spaceChar){
				spaceCount ++;
			}else{
				System.arraycopy(charArray, i, destArray, length-spaceCount, spaceCount);
				destArray[length] = ' ';
				spaceCount = 0;
			}
		}
		if (spaceCount > 0){
			System.arraycopy(charArray, 0, destArray, totalLength-spaceCount, spaceCount);
		}
		return String.valueOf(destArray);
	}

My Solution without Split to avoid regex cost
System.out.println(revereseWords("This is test",' '));

Without use of any array split....

static void ReverseString(String ReverseString)
        {
            int endPrint = ReverseString.Length-1;

            for (int i = ReverseString.Length-1; i >= 0; i--)
            {
                if (ReverseString[i] == ' ' || i == 0)
                {
                    for (int j = i; j <= endPrint; j++)
                    {
                        Console.Write(ReverseString[j]);
                    }
                    endPrint = i;
                    Console.Write(" ");
                }
                
            }
        }

Ruby Code without using built in function-

data = String.new("This is Test")
l=data.length
p=0
a = Array.new
i=l-1
while i>=0 do
 a[p]= data[i]
 p=p+1
 i=i-1
end 
arr= a.inject(:+)
puts arr

-----Ruby Code------
str=String.new
n=String.new
str='This is a new year'
l=str.length
puts l
len=l-1
for i in 0...l
n[i]=str[len]
len=len-1
end
print n

Heres the solution in C without using stack

#include<stdio.h>

int main(){
	char string[] = " Hello i am shashank and how are you man!!";
	int i=0;
	int j=0;
	while(string[i] != '\0')
		i++;
	i--;
	while(i>=0){
		if(string[i] == ' ' || i==0){
			j=i+1;
			while(string[j] != ' ' && string[j] != '\0')
				printf("%c",string[j++]);
			printf(" ");
	  }
	  i--;
	}
}

Here my C++ version:

string get_words_reverse(string &s) {
int j = s.size() - 1;

for(int i = 0; i < s.size()/2.0; i++) {
swap(s[i], s[j]);
j--;
}

for(int i = 0; i <= s.size(); i++) {
if(s[i] == ' ' || i == s.size()) {
int end = i - 1;
int len = end - start;

for(int j = 0; j <= len/2.0; j++) {
swap(s[start], s[end]);
start++;
end--;
}

start = i + 1;
}
}

return s;
}

>>> a = "This is a test"
>>> a[-1::-1]
'tset a si sihT'

public void check()
{
index=0;
for(int i=0;i<input.length();i++)
{
if(i<(input.length()-1))
{
index=input.indexOf(" ");
if(index!=-1)
{
output= input.substring(0,index)+" "+output;
input=input.substring(index+1);
i=0;
}

}

else
{
output= input.substring(0)+" "+output;

}
}

System.out.println(output);
}

public String reverseString(String s) {
        if (s == null || s.length() <= 1) {
            return s;
        } else {
            return reverseString(s.substring(1)) + s.charAt(0);
        }
    }

import java.util.Stack;

public class PrintLineInReverse {

	public static String reverseString(String str){
		Stack<String> sk = new Stack<String>();
		StringBuilder sb = new StringBuilder();
		int lasti=0; boolean flag=false;
		String st;
		for(int i=0;i<str.length();i++){
			if(str.charAt(i)==' '){
				st = str.substring(lasti, i);
				sk.push(st);
				flag = true;
				continue;
			}
			if(flag){
				flag = false;
				lasti = i;
			}
		}
		st = str.substring(lasti, str.length());
		sk.push(st);
		while(!sk.isEmpty()){
			sb.append(sk.pop()+" ");
		}
		return sb.toString();
	}
	public static void main(String[] args) {
		String str = "This is test sdfsd";
		System.out.println(reverseString(str));
	}

}

String sentence = "This is test";
		String[] words = sentence.split(" ");
		for(int i = words.length-1 ; i >=0 ; i-- )
		{
			System.out.print(words[i]);
			if(i > 0)
				System.out.print(" ");
		}

	}

Here is the C++ code:
int main() {

	string cszStr = "I am tester trying for new opportunities";

	int len = cszStr.length();

	for (int i=0,x=0; i<= len; i++, x++)
	{
		if (32 == (int)cszStr[len-i] || i == len)
		{
			for (int y = len-i; y <= ((len-i)+x); y++)
				cout << cszStr[y];
			x = 0;
		}
	}

	return 0;
}

import java.util.*;
public class ReverseStringByWords{

     public static void main(String []args){
         String str = "this is test";
         String[] arr = str.split(" ");
         
         for(int i=2;i>=0;i--){
             System.out.println(arr[i]);
         }
     }
}

String test= "This is test";
		String [] reverseTest= test.split(" ");
		for (int i= reverseTest.length-1; i>=0; i--){
			System.out.println(reverseTest[i]);

}

package programs;

public class StringSplit {

public static void main(String[] args)
{
String str="This is Test";
String[] arr=str.split(" " );//splits the array by space
System.out.println(arr.length);
System.out.println("" +str);
for(int i=arr.length-1;i>=0;i--)
{
System.out.print(" "+arr[i]);

}
}
}

package programs;

public class StringSplit {

public static void main(String[] args)
{
String str="This is Test";
String[] arr=str.split(" " );//splits the array by space
System.out.println(arr.length);
System.out.println("" +str);
for(int i=arr.length-1;i>=0;i--)
{
System.out.print(" "+arr[i]);

}
}
}

This is my C++ version, O(n) complexity and O(1) space (in-place). First reverses the entire string. Then reverse each word separated by one or more spaces.

#include <iostream>

void my_reverse(std::string& str, size_t begin, size_t end)
{
    while (begin < end)
        std::swap(str[begin++], str[end--]);
}

std::string reverse_words(std::string& phrase)
{
    // Reverse the entire string
	my_reverse(phrase, 0, phrase.size() - 1);
    
    // Reverse each word
    size_t begin_pos = 0;
    while (begin_pos != std::string::npos) {
        size_t end_pos = phrase.find(' ', begin_pos);
        if (end_pos == std::string::npos)
            end_pos = phrase.length();
        my_reverse(phrase, begin_pos, end_pos - 1);
        begin_pos = phrase.find_first_not_of(' ', end_pos + 1);
    }
    return phrase;
}

int main() {
	std::string str = "This is a test";
	std::cout << reverse_words(str) << std::endl;
	return 0;
}

line = 'This is test'
print line.split()[::-1]

this is my CPP code working fine with few test.

#include <cstdlib>
#include <iostream>
#include <string>

using namespace std;

string  stringRev(string & Str,int len)
{
 string arr[len];
 int i=0,j=0;
 int count =0;
          while(Str[i]!='\0') 
          {
                              
              if(Str[i]==' ')
              {                
                 arr[j]= Str.substr(count,i-count);
                 cout<<Str.substr(count,i-count)<<endl;
                 j++;
                           i++;
                 count=i;
              }
              else
              {
                  i++;
              }
                           
          }
          arr[j]=  Str.substr(count,i-count);   
          cout<<Str.substr(count,i-count)<<endl;
          string strnew;
          for(int k=len-1;k>=0;k--)
          {
                  strnew.append(arr[k]);
                  strnew.append(" ");                 
          } 
          cout<<strnew<<endl;
 return strnew;
}
int no_of_space(string &str)
{
 int len=0;
 int i=0;
 while(str[i]!= '\0')
 {
  if (str[i]==' ')
  {
                len++;
  }
  i++;
 }   
 len++;
 cout<<"Length :"<<len<<endl;
 return len;
}

int main(int argc, char *argv[])
{
    string str="Priyanshu is wrong what about this question";
    int len = no_of_space(str);
    string rtn = stringRev(str,len);
    cout<<rtn<<endl;
    system("PAUSE");
    return EXIT_SUCCESS;
}

reverse(char *p,stack &s)
{
   if(*(p + 1) != '\0')
   {
     reverse(++p);
   }
   
   if(*p != ' ')
   {
     s.push(p);
   }
   else
   {
     s.print(); // This pops and prints all the chars pushed so far
   }   
}