Number Of Occurence

One Of very commonly asked problem in Job Interviews is To find number of occurrence of given word in given paragraph . This very easy question but people still make mistakes .

How to do it  :-

• Find first occurrence of first character of word in paragraph 
• If found >>  from that point check next character of word match with next character of paragraph
• Check until last character of word match with consecutive next character of paragraph
• If all character match increment  count by 1.
• Repeat all above statement but now search perform on paragraph started at index of end of last character until which our search is completed 

C++ Program to find no of Occurrence :-

1. /*
2.  To check Occurrence of Given word in Given Paragraph
3.  >>Case sensitive
4. */
5. #include<iostream>
6. #include<string.h>
7. using namespace std;
8. main(){
9.         char para[500];
10.         char word[20];
11.         int i,j,flag,count=0;
12.         cout<<"Enter Paragraph String : ";
13.         gets(para);
14.         cout<<"Enter Word to search : ";
15.         gets(word);
16.        
17.         i=0;
18.         while(i<strlen(para)){
19.                 if(word[0]==para[i]){
20.                 // if first element of word found check for rest of element
21.                 // of word at consecutive position if all match found increment count
22.                         i++;              
23.                         j=1;
24.                         flag=1; //flag == True
25.                         while(j<strlen(word)){
26.                                 if(word[j]!=para[i]){
27.                                         flag=0; //Mismatch found So flag=False
28.                                         break;  
29.                                 }
30.                                 i++;
31.                                 j++;
32.                         }
33.                         if(flag) //if flag==True
34.                            count++;
35.                 }
36.                 else
37.                   i++;
38.         }
39.         cout<<"No of Occurence :: "<<count;
40.         return 0;
41. }

Note :-  We can use this technique  to find all URL in a given webpage  

Python >> Find Number of Occurrences :-

1. # Find Occurrence Of Given Word In Given Paragraph
2. # case-Insensitive
4. def find_occ(para,word):
5.     '''
6.     Find Occurrence of word in para and return no of occurrence
7.     ->case Insensitive Search
8.     (string,string)->int
9.    
10.    '''
11.     Occurrence=0
12.     para=para.lower() #all in lowercase
13.     word=word.lower()
14.     index=-1
15.     while True:
16.         index=para.find(word,index+1) #if next word is not found return -1
17.         if index!=-1:
18.             Occurrence +=1
19.         else:
20.             break
21.     return Occurrence
23. if __name__=='__main__':
24.     para=raw_input('Enter Paragraph :')
25.     word=raw_input("Enter word to Search :")
27.     print 'Occurence of "',word,'" in given paragraph is ::',find_occ(para,word)
28.     raw_input('\n\nhttp://beginer2cs.blogspot.com/')

Output:-