Unable to write string window code properly pls help

#1

https://ide.codingblocks.com/s/283993 correct this code pls

#2

Follow the steps given below:

  1. First check if the length of string is less than the length of the given pattern, if yes then “ no such window can exist “.
  2. Store the occurrence of characters of the given pattern in a hash_pat[].
  3. Start matching the characters of pattern with the characters of string i.e. increment count if a character matches.
  4. Check if (count == length of pattern ) this means a window is found.
  5. If such window found, try to minimize it by removing extra characters from the beginning of the current window.
  6. Update min_length.
  7. Print the minimum length window.
#3

can you pls send me a code for refrence or just correct my code pls

#4

string findSubString(string str, string pat)

{

int len1 = str.length();

int len2 = pat.length();

// check if string's length is less than pattern's

// length. If yes then no such window can exist

if (len1 < len2)

{

cout << "No such window exists" ;

return "" ;

}

int hash_pat[no_of_chars] = {0};

int hash_str[no_of_chars] = {0};

// store occurrence ofs characters of pattern

for ( int i = 0; i < len2; i++)

hash_pat[pat[i]]++;

int start = 0, start_index = -1, min_len = INT_MAX;

// start traversing the string

int count = 0; // count of characters

for ( int j = 0; j < len1 ; j++)

{

// count occurrence of characters of string

hash_str[str[j]]++;

// If string's char matches with pattern's char

// then increment count

if (hash_pat[str[j]] != 0 &&

hash_str[str[j]] <= hash_pat[str[j]] )

count++;

// if all the characters are matched

if (count == len2)

{

// Try to minimize the window i.e., check if

// any character is occurring more no. of times

// than its occurrence in pattern, if yes

// then remove it from starting and also remove

// the useless characters.

while ( hash_str[str[start]] > hash_pat[str[start]]

|| hash_pat[str[start]] == 0)

{

if (hash_str[str[start]] > hash_pat[str[start]])

hash_str[str[start]]--;

start++;

}

// update window size

int len_window = j - start + 1;

if (min_len > len_window)

{

min_len = len_window;

start_index = start;

}

}

}

// If no window found

if (start_index == -1)

{

cout << "No such window exists" ;

return "" ;

}

// Return substring starting from start_index

// and length min_len

return str.substr(start_index, min_len);

}