leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commitd66cc2fc391d504ec4e8d77df4f887ea70d7ac34
parent2af78f2f8c305bdff64e5babdca52972933e0cfb
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateWed, 8 Feb 2023 20:08:12 +0100

Dynamic Programming I: Day 19

Diffstat:
AProblems/0072.cpp|+++++++++++++++++++
AProblems/1143.cpp|+++++++++++++++++++++++++++++++++++++
MREADME.md|++

3 files changed, 58 insertions(+), 0 deletions(-)

diff --git a/Problems/0072.cpp b/Problems/0072.cpp

@@ -0,0 +1,19 @@

class Solution {
public:
int minDistance(string word1, string word2) {
int n = word1.size(), m = word2.size();
vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
for (int i = 1; i <= n; i++) dp[i][0] = i;
for (int j = 1; j <= m; j++) dp[0][j] = j;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (word1[i - 1] == word2[j - 1])
dp[i][j] = dp[i - 1][j - 1];
else
dp[i][j] = min(dp[i - 1][j - 1], min(dp[i][j - 1], dp[i - 1][j])) + 1;
}
}
return dp.back().back();
}
};

diff --git a/Problems/1143.cpp b/Problems/1143.cpp

@@ -0,0 +1,37 @@

// Top-down DP
class Solution {
int search(const string &text1, const string &text2, int si, int sj,
vector<vector<int>> &dp) {
if (si == text1.size() || sj == text2.size()) return 0;
if (dp[si][sj] != -1) return dp[si][sj];
int len = 0, i = si, j = sj;
while (i < text1.size() && j < text2.size() && text1[i] == text2[j])
i++, j++, len++;
if (i == text1.size() || j == text2.size()) return dp[si][sj] = len;
return dp[si][sj] = len + max(search(text1, text2, i + 1, j, dp),
search(text1, text2, i, j + 1, dp));
}
public:
int longestCommonSubsequence(string text1, string text2) {
vector<vector<int>> dp(text1.size(), vector<int>(text2.size(), -1));
return search(text1, text2, 0, 0, dp);
}
};
// Bottom-up DP
class Solution {
public:
int longestCommonSubsequence(string text1, string text2) {
vector<vector<int>> dp(text1.size() + 1, vector<int>(text2.size() + 1, 0));
for (int i = 0; i < text1.size(); i++)
for (int j = 0; j < text2.size(); j++)
if (text1[i] == text2[j])
dp[i + 1][j + 1] = 1 + dp[i][j];
else
dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1]);
return dp.back().back();
}
};

diff --git a/README.md b/README.md

@@ -66,6 +66,7 @@ for solving problems.

| 0066 | Easy | [Plus One](Problems/0066.cpp) |
| 0067 | Easy | [Add Binary](Problems/0067.cpp) |
| 0070 | Easy | [Climbing Stairs](Problems/0070.cpp) |
| 0072 | Hard | [Edit Distance](Problems/0072.cpp) |
| 0074 | Medium | [Search a 2D Matrix](Problems/0074.cpp) |
| 0075 | Medium | [Sort Colors](Problems/0075.cpp) |
| 0077 | Medium | [Combinations](Problems/0077.cpp) |

@@ -322,6 +323,7 @@ for solving problems.

| 1099 | Easy | [Replace Elements with Greatest Element on Right Side](Problems/1099.cpp) |
| 1129 | Medium | [Shortest Path with Alternating Colors](Problems/1129.cpp) |
| 1137 | Easy | [N-th Tribonacci Number](Problems/1137.cpp) |
| 1143 | Medium | [Longest Common Subsequence](Problems/1143.cpp) |
| 1202 | Medium | [Smallest String With Swaps](Problems/1202.cpp) |
| 1209 | Medium | [Remove All Adjacent Duplicates in String II](Problems/1209.cpp) |
| 1290 | Easy | [Convert Binary Number in a Linked List to Integer](Problems/1290.cpp) |