leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commitd16a95b5a7fcc0f39540c993a3b89728d97919be
parent4faa838ae100c53005b7e71f98cd7157e2d458b0
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateMon, 25 Nov 2024 20:13:52 +0100

Daily Problem

Diffstat:
AProblems/0773.cpp|+++++++++++++++++++++++++++++++++++++++++++++++++++
MREADME.md|+

2 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/Problems/0773.cpp b/Problems/0773.cpp

@@ -0,0 +1,51 @@

class Solution {
using type_t = pair<uint32_t, uint32_t>;
static type_t encode(const vector<vector<int>> &board) {
uint32_t n2p = 0; // number to position
uint32_t p2n = 0; // position to number
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 3; j++) {
const int idx = i * 3 + j;
n2p |= idx << (board[i][j] * 3);
p2n |= board[i][j] << (idx * 3);
}
}
return {n2p, p2n};
}
public:
int slidingPuzzle(const vector<vector<int>> &board) const {
static const vector<vector<int>> adj = {{1, 3}, {0, 2, 4}, {1, 5}, {0, 4}, {1, 3, 5}, {2, 4}};
unordered_set<uint32_t> seen;
queue<type_t> q;
q.push(encode(board));
for (int lvl = 0; !q.empty(); lvl++) {
for (int k = size(q); k > 0; k--) {
const auto [n2p, p2n] = q.front();
q.pop();
if (n2p == 0x23445) return lvl;
const auto p = n2p & 0x7; // position of zero
for (const auto sp : adj[p]) { // position to swap
const auto sn = (p2n >> (sp * 3)) & 0x7; // number to swap
const auto sn2p = (n2p & ~((0x7 << (sn * 3)) | (0x7 << (0 * 0)))) | (p << (sn * 3)) | sp;
const auto sp2n = (p2n & ~((0x7 << (sp * 3)) | (0x7 << (p * 3)))) | (sn << (p * 3));
if (!seen.count(sn2p)) {
q.emplace(sn2p, sp2n);
seen.insert(sn2p);
}
}
}
}
return -1;
}
};

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

@@ -569,6 +569,7 @@ reference and a base for solving problems.

| 0763 | Medium | [Partition Labels](Problems/0763.cpp) |
| 0767 | Medium | [Reorganize String](Problems/0767.cpp) |
| 0769 | Medium | [Max Chunks To Make Sorted](Problems/0769.cpp) |
| 0773 | Hard | [Sliding Puzzle](Problems/0773.cpp) |
| 0779 | Medium | [K-th Symbol in Grammar](Problems/0779.cpp) |
| 0781 | Medium | [Rabbits in Forest](Problems/0781.cpp) |
| 0783 | Easy | [Minimum Distance Between BST Nodes](Problems/0783.cpp) |