leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commitaab0ccefae5496d4cff8c99b0f9844bc6e1fb35a
parent080fd5e402784bf5a9671c93e60439957a2b6d6c
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateSun, 12 Feb 2023 11:55:43 +0100

Data Structure II: Day 9

Diffstat:
AProblems/0187.cpp|++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
MREADME.md|+

2 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/Problems/0187.cpp b/Problems/0187.cpp

@@ -0,0 +1,58 @@

// Left to right
class Solution {
public:
vector<string> findRepeatedDnaSequences(string s) {
if (s.size() <= 10) return {};
unordered_map<string, int> um;
vector<string> res;
string sec = "";
for (int i = 0; i < 10; i++) sec += s[i];
um[sec]++;
for (int i = 10; i < s.size(); i++) {
sec = sec.substr(1) + s[i];
if (um[sec]++ == 1) res.push_back(sec);
}
return res;
}
};
// Right to left
class Solution {
public:
vector<string> findRepeatedDnaSequences(string s) {
if (s.size() <= 10) return {};
unordered_map<string, int> um;
vector<string> res;
string sec = "";
for (int i = s.size() - 1; i >= s.size() - 10; i--) sec = s[i] + sec;
um[sec]++;
for (int i = s.size() - 10 - 1; i >= 0; i--) {
sec.pop_back();
sec = s[i] + sec;
if (um[sec]++ == 1) res.push_back(sec);
}
return res;
}
};
// Bit hacking
class Solution {
public:
vector<string> findRepeatedDnaSequences(string s) {
unordered_map<unsigned, int> um;
vector<string> res;
for (unsigned i = 0, sec = 0; i < s.size(); i++) {
sec = sec << 3 & 0x3FFFFFFF | s[i] & 7;
if (um[sec]++ == 1) res.push_back(s.substr(i - 9, 10));
}
return res;
}
};

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

@@ -132,6 +132,7 @@ for solving problems.

| 0167 | Medium | [Two Sum II - Input Array Is Sorted](Problems/0167.cpp) |
| 0169 | Easy | [Majority Element](Problems/0169.cpp) |
| 0173 | Medium | [Binary Search Tree Iterator](Problems/0173.cpp) |
| 0187 | Medium | [Repeated DNA Sequences](Problems/0187.cpp) |
| 0189 | Medium | [Rotate Array](Problems/0189.cpp) |
| 0190 | Easy | [Reverse Bits](Problems/0190.cpp) |
| 0191 | Easy | [Number of 1 Bits](Problems/0191.cpp) |