CareerCup

// Time : O(n), Space : O(n)
// In java, string manipulations cannot be done in constant space
public static String reverseSetence(String str) {
		StringBuilder sb = new StringBuilder(str);
		Pattern p = Pattern.compile("[a-zA-Z0-9]+");
		Matcher m = p.matcher(str);
		while (m.find()) {
			reverse(sb, m.start(), m.end() - 1);
		}
		return sb.toString();
	}

	public static void reverse(StringBuilder sb, int l, int r) {
		while (l < r) {
			swap(sb, l++, r--);
		}
	}

	public static void swap(StringBuilder sb, int i, int j) {
		char temp = sb.charAt(i);
		sb.setCharAt(i, sb.charAt(j));
		sb.setCharAt(j, temp);
	}

#include<iostream>
#include<vector>
#include<string>

using namespace std;

string func(string s){

        vector<char> v;
        string s2="";

        for(int i=0;i<s.size();i++){
                if(s[i]==' ' || i==s.size()-1){
                        if(i==s.size()-1) v.push_back(s[i]);
                        while(v.size()){
                                s2=s2+v[v.size()-1];
                                v.pop_back();
                        }
                        s2=s2+' ';
                }
                else
                        v.push_back(s[i]);
        }
        return s2;
}

int main(){

        string s = "We will rock you !";
        cout<<func(s)<<endl;

        return 0;
}

python:

sentence = "This is a sentence"
reverse = " ".join(word[::-1] for word in sentence[::-1].split(" "))
print reverse	# sentence a is This

1 #!/usr/bin/python
2
3 import sys
4 import time
5
6
7
8 def rev_string(input_data):
9 # Create an empty List Obj for later use
10 final_list = []
11 # Transform and fill a local Obj with the input data
12 my_list = list(input_data)
13 # Getting the range(Len of the list -1, End, Step_Val)
14 range_data = range(len(my_list) - 1, -1, -1)
15 # Start a for loop to step the range data
16 for data_step in range_data:
17 # Fill the list Obj we created at the start
18 final_list.append(my_list[data_step])
19 # once we have appended the data, we then join it back and return
20 final_list = ''.join(final_list)
21 return final_list
22
23
24 def main():
25 # input data
26 data = "This is a string!"
27 # Show the user data before
28 print "Data Before: %s" % data
29 # call the rev function to flip the data
30 data = rev_string(data)
31 # Show the user data after
32 print "Data After: %s" % data
33
34 if __name__ == "__main__":
35 sys.exit(main())



Example output -- >
Data Before: This is a string!
Data After: !gnirts a si sihT

// c or c++ version
// no error checking is done
void revString(char *str, int start, int end)
{
	char temp;
	while (start < end) {
		temp = str[start];
		str[start] = str[end];
		str[end] = temp;
		start++;
		end--;
	}
}
// Assumption - one space between words
void revSentence( char *sen)
{
	int len = strlen(sen);
	if (len == 0 || len == 1) return;
	// reverse string
	revString(sen, 0, len-1);
	int start =0;
	for (int i=0; i<len; i++) {
		// if it is space, reverse the word
		if (sen[i] == ' ') {
			revString(sen, start, i-1);
			start = i+1;
		}
	}
	// reverse last word
	revString(sen, start, len-1);
}

def ReverseString(str)
print(str[::-1])

//test
assert ReverseString("hello world") = "dlrow oleo"

In Javascript:
function RevSentence(str)
{
var ss = str.split("").reverse().join("");
console.log(ss);

}

RevSentence("Welcome to jurassic park");

reverse the string and print words from en

#include<stdio.h>
#include<string.h>

int main() {
char str[100], temp;
int i, j = 0;

printf("\nEnter the string :");
gets(str);
i = 0;
j = strlen(str) - 1;
while (i < j) {
temp = str[i];
str[i] = str[j];
str[j] = temp;
i++;
j--;
}
printf("\nReverse string is :%s", str);
return (0);
}