leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commitb63855cf7ac47e69cc0454549065d2c5cbb4f430
parenta0d50931c2456237b75f86e5d2f4a0fe8f780025
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateFri, 1 Nov 2024 14:10:25 +0100

Daily Problem, 1 Random

Diffstat:
AProblems/0336.cpp|++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AProblems/1957.cpp|++++++++++++++++++
MREADME.md|++

3 files changed, 86 insertions(+), 0 deletions(-)

diff --git a/Problems/0336.cpp b/Problems/0336.cpp

@@ -0,0 +1,66 @@

static bool isPalindrome(const string &s, int i, int j) {
while (i < j) {
if (s[i++] != s[j--]) return false;
}
return true;
}
class Trie {
struct Node {
Node *children[26] = {0};
vector<int> suffix;
int idx = -1;
} root;
public:
void insert(const string &s, int idx) {
Node *crnt = &root;
for (int i = size(s) - 1; i >= 0; i--) {
auto &child = crnt->children[s[i] - 'a'];
if (!child) child = new Node();
if (isPalindrome(s, 0, i)) crnt->suffix.push_back(idx);
crnt = child;
}
crnt->suffix.push_back(idx);
crnt->idx = idx;
}
void query(const string &s, int idx, vector<vector<int>> &res) const {
const Node *crnt = &root;
const int n = size(s);
for (int i = 0; i < n; i++) {
if (crnt->idx != -1 && crnt->idx != idx && isPalindrome(s, i, n - 1)) {
res.push_back({idx, crnt->idx});
}
crnt = crnt->children[s[i] - 'a'];
if (!crnt) return;
}
for (const auto n : crnt->suffix) {
if (n == idx) continue;
res.push_back({idx, n});
}
}
};
class Solution {
public:
vector<vector<int>> palindromePairs(const vector<string> &words) const {
const int n = size(words);
vector<vector<int>> res;
Trie trie;
for (int i = 0; i < n; i++)
trie.insert(words[i], i);
for (int i = 0; i < n; i++)
trie.query(words[i], i, res);
return res;
}
};

diff --git a/Problems/1957.cpp b/Problems/1957.cpp

@@ -0,0 +1,18 @@

class Solution {
public:
string makeFancyString(string &s) const {
char prev = '\0';
int i = 0, cnt = 0;
for (const char c : s) {
if (c == prev)
cnt++;
else
prev = c, cnt = 1;
if (cnt <= 2) s[i++] = c;
}
s.resize(i);
return s;
}
};

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

@@ -307,6 +307,7 @@ reference and a base for solving problems.

| 0331 | Medium | [Verify Preorder Serialization of a Binary Tree](Problems/0331.cpp) |
| 0332 | Hard | [Reconstruct Itinerary](Problems/0332.cpp) |
| 0334 | Medium | [Increasing Triplet Subsequence](Problems/0334.cpp) |
| 0336 | Hard | [Palindrome Pairs](Problems/0336.cpp) |
| 0337 | Medium | [House Robber III](Problems/0337.cpp) |
| 0338 | Easy | [Counting Bits](Problems/0338.cpp) |
| 0341 | Medium | [Flatten Nested List Iterator](Problems/0341.cpp) |

@@ -1105,6 +1106,7 @@ reference and a base for solving problems.

| 1945 | Easy | [Sum of Digits of String After Convert](Problems/1945.cpp) |
| 1947 | Medium | [Maximum Compatibility Score Sum](Problems/1947.cpp) |
| 1954 | Medium | [Minimum Garden Perimeter to Collect Enough Apples](Problems/1954.cpp) |
| 1957 | Easy | [Delete Characters to Make Fancy String](Problems/1957.cpp) |
| 1962 | Medium | [Remove Stones to Minimize the Total](Problems/1962.cpp) |
| 1963 | Medium | [Minimum Number of Swaps to Make the String Balanced](Problems/1963.cpp) |
| 1964 | Hard | [Find the Longest Valid Obstacle Course at Each Position](Problems/1964.cpp) |