CareerCup

A> Reverse the whole string first.
B> Reverse individual words of the output string from step A.

char* ReverseAllWords(char* text) {
    int lindex = 0;
    int len = strlen(text) - 1;
    if (len > 1) {
	
        //reverse complete string
        text = ReverseString( text, 0, len );

        //reverse each word
        for (int rindex = 0; rindex <= len; rindex++) {
            if (rindex == len || text[rindex] == ' ') {
                text = ReverseString(text, lindex, rindex - 1);
                lindex = rindex + 1;
            }
        }
    }
    return text;
}

char* ReverseString(char* str, int begin, int end) {
    while (begin < end) {
        char tempc = str[begin];
        str[begin++] = str[end];
        str[end--] = tempc;
    }
    return str;
}

Steps to solve this problem:
1) Start from the end of the string.
2) Iterate each character until an empty char.
3) When an empty char is found, keep that index and from that index to the end copy the string into temp.
4) do step 3 untill you reach start of the original string.

C# code for same;

private static void ReverseAStringByWords()
{
string s = "Reverse this string by words";
string temp = string.Empty;
int k = s.Length;
int n = 0;

for (int i = k; i >= 0; i--)
{
if (i == 0 || s[i - 1] == ' ')
{
for (int j = i; j < k; j++)
{
temp += s[j];
}
temp += ' ';
k = i;
}
}
Console.WriteLine(temp);
}

How about this, it is java.

public static void main(String[] args){
		
		char[] cc={'N','o','r','t','h','e','r','n',' ','C', 'a', 'l', 'i','f', 'o','r','n','i','a',' ','U','S','A'};
		
		int start=cc.length-1;
		for(int i=cc.length-1; i>=0; i--){
			
			if(cc[i]==' ' || i==0)
			{
				for(int j=i; j<=start; j++){
					System.out.print(cc[j]);
				}
				start=i;
			}
		}
		
	}

public class SentenceReverse {
    private static void printReverse(char[] chars){
        int end  = chars.length;
        
        for(int i = chars.length - 1; i >= 0; i--){
            if(i == 0 || chars[i-1] == ' '){
                int k = i;
                while(k < end){
                    System.out.print(chars[k]);
                    k++;
                }
                end = i;
                System.out.print(" ");
            }
        }
    }
    public static void main(String[] args) {
        printReverse("Northern California USA".toCharArray());
    }
}

char *rev(char* s){
	char *temp = malloc(strlen(s)*sizeof(char));
	int cnt=0,j=0,i;
	for(i=strlen(s);i>0;i--){
		if(s[i]=='\0'){
			//copy from cnt to i to cnt
			for(k=cnt;k<=i;k++){
				temp[j]=s[k];
				j++;
			}
			cnt =i;
		}
	}	
return temp;
}

for(i = S.length -1 ;i>=-1;i--){
if(S[i] == ' ' || i == -1){
j = i + 1 ;
while(j!= S.length && S[j]!=' '){
console.log(S[j]) ;
j++ ;
}
console.log(' ');
}
}

Solution without using any char temp.

for(i = S.length -1 ;i>=-1;i--){
    if(S[i] == ' ' || i == -1){
      j = i + 1 ;
      while(j!= S.length && S[j]!=' '){
	console.log(S[j]) ;
       j++ ;
       }
console.log(' ');
     }
}

Solution without any char temp.