added count word.c

Author: UG-SEP

Strings/Count_word.c

@@ -0,0 +1,66 @@
+/*  Program to find the total numbers of words in a sentence  */
+#include<stdio.h>
+#include<string.h>
+#include<stdlib.h>
+
+//Function which calculate and return total numbers of words
+int count_words(char *sen)
+{
+    int i=0,check=1,word=0;
+    //dynamically allocating memory
+    realloc(sen,strlen(sen)+1);
+    //until i is less then length of sen variable the loop will run
+    while(strlen(sen)>i)
+    {
+/*if sen[i]th index value is not equal to space and i is not the last index number because
+the last index no. contain null and null is not alphabet so we not need to treat it as a alphabet*/
+        if(sen[i]!=' '&&i!=strlen(sen)-1)
+        {
+            //if check is equal to 1(first time word occurrence after space)
+            if(check==1)
+            {
+                //increment word and assign 0 to check
+                word++;
+            check=0;
+            }
+        }
+        // if the sen[i]th index no. value is a space or null then run else
+        else
+        {
+            //assign 1 to check
+            check=1;
+        }
+        //increment i by 1
+        i++;
+    }
+    return word;
+}
+//driver code
+int main()
+{
+    //initialize required variables
+    char *sen,res;
+    // dynamically locating the address in sen variable
+    sen=(char*)malloc(sizeof(char)*1000);
+    printf("Enter a sentence: ");
+    //taking input
+    fgets(sen,1000,stdin);
+    // resizing the sen variable length so memory wastage can be prevent
+    sen=(char*)realloc(sen,strlen(sen)+1);
+    // calling count_words function which will return total words in res variable
+    res=count_words(sen);
+    //printing the total words
+    printf("Total number of words: %d",res);
+}
+/*
+Test case 1:
+Input: Enter a sentence:         DSA    is    a Important            Topic
+Output: Total number of words: 5
+
+Test case 2:
+Input: Enter a sentence: Who are you?
+Output: Total number of words: 3
+
+Time Complexity O(n) where n is the length of string
+
+*/