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Refactoring code

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This commit is contained in:
Ashish Bhanu Daulatabad
2021-03-07 11:01:11 +05:30
parent fc6e726860
commit 232d4f5eba
1 changed files with 46 additions and 39 deletions
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85
dynamic_programming/abbreviation.cpp
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@@ -1,19 +1,25 @@
/**
* @file
* @brief Implementation of Abbrievation
* (https://www.hackerrank.com/challenges/abbr/problem)
*
* @details
* You can perform the following operations on the string a:
* Capitalize zero or more of a's lowercase letters.
* Delete all of the remaining lowercase letters in a.
* Given two strings, a and b, determine if it's possible to make a equal to b
* as described. If so, print YES on a new line. Otherwise, print NO.
* Given two strings, a and b, determine if it's possible to make a equal to
* b You can perform the following operations on the string a:
* 1. Capitalize zero or more of a's lowercase letters.
* 2. Delete all of the remaining lowercase letters in a.
*
* E.g., For example, given a = AbcDE and b = ABDE, in a we can convert 'b' and
* delete 'c' to match b. If a = AbcDE and b = AFDE, matching is not possible
* because letters may only be capitalized or discarded, not changed
* ##Algorithm
* The idea is in the problem statement itself: iterate through characters of
* string a and b (for character indexes i and j respectively):
* 1. If a[i] and b[j] are equal, then move to next position
* 2. If a[i] is lowercase of b[j], then explore two possibilities:
* a. Capitalize or
* a. Skip a[i]
* 3. If the a[i] is not uppercase, just discard the char, else return false
*
* Time Complexity (O(|a|*|b|)) where |a| => length of string
* @author Ashish Daulatabad (https://github.com/AshishYUO)
*/
#include <cassert>
@@ -43,45 +49,45 @@ namespace abbreviation {
* @param j: start of string j
* @returns bool whether s can be converted to t
*/
bool abbreviation_recursion(std::vector<std::vector<bool>> &memo,
std::vector<std::vector<bool>> &visited,
bool abbreviation_recursion(std::vector<std::vector<bool>> *memo,
std::vector<std::vector<bool>> *visited,
const std::string &s, const std::string &t,
int i = 0, int j = 0) {
bool ans = memo[i][j];
// If the check is finished, then return true
if (i == s.size() and j == t.size())
bool ans = memo->at(i).at(j);
if (i == s.size() && j == t.size()) {
return true;
// if s string is converted but the check is not complete, return false
else if (i == s.size() and j != t.size())
} else if (i == s.size() && j != t.size()) {
// result t is not converted, return false
return false;
else if (!visited[i][j]) {
} else if (!visited->at(i).at(j)) {
/**
* (s[i] == t[j]): if s char at position i is equal to t char at
* position j, then s character is a capitalized one, move on to next
* character
* s[i] - 32 == t[j]: if s char at position is lowercase of t
* at position j, then explore two possibilites:
* s[i] - 32 == t[j]: if s[i] character is lowercase of t[j] then
* explore two possibilites:
* 1. convert it to capitalized and move both to next pointer (i + 1, j
* + 1)
* 2. Discard the character and move to next char (i + 1, j)
* 2. Discard the character (s[i]) and move to next char (i + 1, j)
*/
if (s[i] == t[j])
if (s[i] == t[j]) {
ans = abbreviation_recursion(memo, visited, s, t, i + 1, j + 1);
else if (s[i] - 32 == t[j])
ans = abbreviation_recursion(memo, visited, s, t, i + 1, j + 1) or
} else if (s[i] - 32 == t[j]) {
ans = abbreviation_recursion(memo, visited, s, t, i + 1, j + 1) ||
abbreviation_recursion(memo, visited, s, t, i + 1, j);
else {
} else {
// if s[i] is uppercase, then cannot be converted, return false
if (s[i] >= 'A' and s[i] <= 'Z')
// else s[i] is lowercase, only option is to discard this character
if (s[i] >= 'A' && s[i] <= 'Z') {
ans = false;
// s[i] is lowercase, only option is to discard this character
else
} else {
ans = abbreviation_recursion(memo, visited, s, t, i + 1, j);
}
}
}
memo[i][j] = ans;
visited[i][j] = true;
return memo[i][j];
(*memo)[i][j] = ans;
(*visited)[i][j] = true;
return (*memo)[i][j];
}
/**
* (iterative dp function) https://www.hackerrank.com/challenges/abbr/problem:
@@ -99,15 +105,16 @@ bool abbreviation(const std::string &s, const std::string &t) {
for (int i = 1; i <= t.size(); ++i) memo[0][i] = false;
for (int i = 1; i <= s.size(); ++i) {
for (int j = 1; j <= t.size(); ++j) {
if (s[i - 1] == t[j - 1])
if (s[i - 1] == t[j - 1]) {
memo[i][j] = memo[i - 1][j - 1];
else if (s[i - 1] - 32 == t[j - 1])
memo[i][j] = (memo[i - 1][j - 1] or memo[i - 1][j]);
else {
if (s[i - 1] >= 'A' and s[i - 1] <= 'Z')
} else if (s[i - 1] - 32 == t[j - 1]) {
memo[i][j] = (memo[i - 1][j - 1] || memo[i - 1][j]);
} else {
if (s[i - 1] >= 'A' && s[i - 1] <= 'Z') {
memo[i][j] = false;
else
} else {
memo[i][j] = memo[i - 1][j];
}
}
}
}
@@ -123,7 +130,7 @@ static void test() {
visited(s.size() + 1, std::vector<bool>(t.size() + 1, 0));
assert(dynamic_programming::abbreviation::abbreviation_recursion(
memo, visited, s, t) == true);
&memo, &visited, s, t) == true);
assert(dynamic_programming::abbreviation::abbreviation(s, t) == true);
s = "XXVVnDEFYgYeMXzWINQYHAQKKOZEYgSRCzLZAmUYGUGILjMDET";
t = "XXVVDEFYYMXWINQYHAQKKOZEYSRCLZAUYGUGILMDETQVWU";
@@ -134,7 +141,7 @@ static void test() {
s.size() + 1, std::vector<bool>(t.size() + 1, 0));
assert(dynamic_programming::abbreviation::abbreviation_recursion(
memo, visited, s, t) == false);
&memo, &visited, s, t) == false);
assert(dynamic_programming::abbreviation::abbreviation(s, t) == false);
s = "DRFNLZZVHLPZWIupjwdmqafmgkg";
@@ -147,7 +154,7 @@ static void test() {
s.size() + 1, std::vector<bool>(t.size() + 1, 0));
assert(dynamic_programming::abbreviation::abbreviation_recursion(
memo, visited, s, t) == true);
&memo, &visited, s, t) == true);
assert(dynamic_programming::abbreviation::abbreviation(s, t) == true);
}