Commit 4fc1471

vil02github-actions[bot]Panquesito7

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fix: segv in longest_palindromic_subsequence.cpp (TheAlgorithms#2461)

* fix: initialise properly res, set properly size of ans * test: add check with empty input * style: use const reference as input type * refactor: add ind_type * style: use reverse interators to b * style: use auto in definition of idx * updating DIRECTORY.md * style: clean-up includes * style: use std::string::size_type in definition of ind_type --------- Co-authored-by: github-actions[bot] <github-actions@users.noreply.github.com> Co-authored-by: David Leal <halfpacho@gmail.com>

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dynamic_programming
- longest_palindromic_subsequence.cpp

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`‎dynamic_programming/longest_palindromic_subsequence.cpp‎`

Lines changed: 15 additions & 17 deletions

Original file line number	Diff line number	Diff line change
`@@ -13,26 +13,26 @@`
`13`	`13`	`* @author [Anjali Jha](https://github.com/anjali1903)`
`14`	`14`	`*/`
`15`	`15`
`16`		`-#include <algorithm>`
`17`		`-#include <cassert>`
`18`		`-#include <iostream>`
`19`		`-#include <vector>`
	`16`	`+#include <cassert> /// for assert`
	`17`	`+#include <string> /// for std::string`
	`18`	`+#include <vector> /// for std::vector`
`20`	`19`
`21`	`20`	`/**`
`22`	`21`	`* Function that returns the longest palindromic`
`23`	`22`	`* subsequence of a string`
`24`	`23`	`*/`
`25`		`-std::string lps(std::string a) {`
`26`		`- std::string b = a;`
`27`		`- reverse(b.begin(), b.end());`
`28`		`- int m = a.length();`
`29`		`- std::vector<std::vector<int> > res(m + 1);`
	`24`	`+std::string lps(const std::string& a) {`
	`25`	`+ const auto b = std::string(a.rbegin(), a.rend());`
	`26`	`+ const auto m = a.length();`
	`27`	`+ using ind_type = std::string::size_type;`
	`28`	`+ std::vector<std::vector<ind_type> > res(m + 1,`
	`29`	`+ std::vector<ind_type>(m + 1));`
`30`	`30`
`31`	`31`	`// Finding the length of the longest`
`32`	`32`	`// palindromic subsequence and storing`
`33`	`33`	`// in a 2D array in bottoms-up manner`
`34`		`- for (int i = 0; i <= m; i++) {`
`35`		`- for (int j = 0; j <= m; j++) {`
	`34`	`+ for (ind_type i = 0; i <= m; i++) {`
	`35`	`+ for (ind_type j = 0; j <= m; j++) {`
`36`	`36`	`if (i == 0 \|\| j == 0) {`
`37`	`37`	`res[i][j] = 0;`
`38`	`38`	`} else if (a[i - 1] == b[j - 1]) {`
`@@ -43,10 +43,10 @@ std::string lps(std::string a) {`
`43`	`43`	`}`
`44`	`44`	`}`
`45`	`45`	`// Length of longest palindromic subsequence`
`46`		`- int idx = res[m][m];`
	`46`	`+ auto idx = res[m][m];`
`47`	`47`	`// Creating string of index+1 length`
`48`		`- std::string ans(idx + 1, '0円');`
`49`		`- int i = m, j = m;`
	`48`	`+ std::string ans(idx, '0円');`
	`49`	`+ ind_type i = m, j = m;`
`50`	`50`
`51`	`51`	`// starting from right-most bottom-most corner`
`52`	`52`	`// and storing them one by one in ans`
`@@ -73,12 +73,10 @@ std::string lps(std::string a) {`
`73`	`73`
`74`	`74`	`/** Test function */`
`75`	`75`	`void test() {`
`76`		`- // lps("radar") return "radar"`
`77`	`76`	`assert(lps("radar") == "radar");`
`78`		`- // lps("abbcbaa") return "abcba"`
`79`	`77`	`assert(lps("abbcbaa") == "abcba");`
`80`		`- // lps("bbbab") return "bbbb"`
`81`	`78`	`assert(lps("bbbab") == "bbbb");`
	`79`	`+ assert(lps("") == "");`
`82`	`80`	`}`
`83`	`81`
`84`	`82`	`/**`

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`‎dynamic_programming/longest_palindromic_subsequence.cpp‎`

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