Minimum Length Word in a string (C++) - c++

Question

Given a string S (that can contain multiple words), you need to find the word which has minimum length.
Note : If multiple words are of same length, then answer will be first minimum length word in the string.
Words are separated by single space only.
Input Format :
String S
Output Format :
Minimum length word
Constraints :
1 <= Length of String S <= 10^5
Sample Input 1 :
this is test string
Sample Output 1 :
is
Sample Input 2 :
abc de ghihjk a uvw h j
Sample Output 2 :
a
Please check what is wrong. There is nothing coming in the output.
Here is the code:
/* input - Input String
* output - Save the result in the output array (passed as argument). You don’t have to
* print or return the result
*/
int length(char input[], int si, int ei){
int len = 0;
for(int i = si; i <= ei; i++){
len++;
}
return len;
}
char getString(char input[], int index){
return input[index];
}
void minLengthWord(char input[], char output[]){
int prev = -1;
int i = 0;
int minLength = 0, len = 0;
int si, ei;
for(; input[i] != '\0'; i++){
if(input[i] == ' '){
int len = length(input, prev + 1, i - 1);
if(len > minLength){
minLength = len;
si = prev + 1;
ei = i - 1;
}
prev = i;
}
}
length(input, prev + 1, i - 1);
if(len > minLength){
minLength = len;
si = prev + 1;
ei = i - 1;
}
for(int i = 0; i < minLength; i++){
output[i] = getString(input, si + i);
}
// Write your code here
}

Answer 1

In fact it is an assignment on testing the knowledge of standard C string functions.
The code shown in the question does not make sense.
For example within the function length
int length(char input[], int si, int ei){
int len = 0;
for(int i = si; i <= ei; i++){
len++;
}
return len;
}
the parameter input is not used. The loop within the function is redundant. The function could be defined simpler like
int length( int si, int ei )
{
return ei - si + 1;
}
Or in the function minLengthWord this if statement
if(len > minLength){
minLength = len;
determines the maximum length of the word instead of the minimum length.
The best approach to define the function is to define it such a way when it returns the position and the length of the minimum word in the given string. Having such an information you always can easily extract the minimum word if it will be required.
Here is a demonstrative program.
#include <iostream>
#include <utility>
#include <cstring>
std::pair<size_t, size_t> minimum_word( const char *s, const char *delim = " \t" )
{
std::pair<size_t, size_t> min = { 0, 0 };
size_t i = 0;
while ( *( s + i ) )
{
i += std::strspn( s + i, delim );
if ( *( s + i ) )
{
size_t n = std::strcspn( s + i, delim );
if ( min.second == 0 || n < min.second )
{
min.first = i;
min.second = n;
}
i += n;
}
}
if ( min.second == 0 ) min.first = i;
return min;
}
int main()
{
const char *s = "Hello John Bradely";
auto min = minimum_word( s );
std::cout << "The minimum word is ";
std::cout.write( s + min.first, min.second ) << '\n';
return 0;
}
The program output is
The minimum word is John
It is easy to change the shown function such a way that it will return a dynamically created array where the minimum word will be copied.
#include <iostream>
#include <utility>
#include <cstring>
char * minimum_word( const char *s, const char *delim = " \t" )
{
std::pair<size_t, size_t> min = { 0, 0 };
size_t i = 0;
while ( *( s + i ) )
{
i += std::strspn( s + i, delim );
if ( *( s + i ) )
{
size_t n = std::strcspn( s + i, delim );
if ( min.second == 0 || n < min.second )
{
min.first = i;
min.second = n;
}
i += n;
}
}
if ( min.second == 0 ) min.first = i;
char *word = new char[min.second + 1]();
std::memcpy( word, s + min.first, min.second );
return word;
}
int main()
{
const char *s = "Hello John Bradely";
char *word = minimum_word( s );
std::cout << "The minimum word is " << word << '\n';
delete [] word;
return 0;
}
The program output is
The minimum word is John

Answer 2

#include<bits/stdc++.h>
#include<iostream>
using namespace std;
void minLengthWord(char input[], char output[]){
int n=strlen(input);
int mini=INT_MAX;
int start=-1;
int cnt=0;
for(int i=0;i<=n;i++){
if(input[i]!=' ' && i!=n){
cnt++;
}
else if(cnt<mini||(i==n &&cnt<mini)){
mini=cnt;
start=i-mini;
cnt=0;
}
else{
cnt=0;
}
}
for(int i=0;i<mini;i++){
output[i]=input[i+start];
}
}
int main(){
char ch[10000], output[10000];
cin.getline(ch, 10000);
minLengthWord(ch, output);
cout << output << endl;
}