leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commit139d1e6bd32f6003fb80e9af1e7cedbbbe0b043e
parentd250236243ac338a7918fcea8415b6582353071b
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateTue, 14 Feb 2023 14:14:27 +0100

LeetCode 75 II: Day 11

Diffstat:
AProblems/0815.cpp|++++++++++++++++++++++++++++++++
MREADME.md|+

2 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/Problems/0815.cpp b/Problems/0815.cpp

@@ -0,0 +1,32 @@

class Solution {
public:
int numBusesToDestination(vector<vector<int>> &routes, int source,
int target) {
if (source == target) return 0;
unordered_map<int, vector<int>> adj;
queue<int> q;
for (int i = 0; i < routes.size(); i++)
for (auto s : routes[i]) adj[s].push_back(i);
if (!adj.count(target)) return -1;
q.push(source);
for (int lvl = 1; !q.empty(); lvl++) {
for (int k = q.size(); k > 0; k--) {
int crnt = q.front();
q.pop();
for (int r : adj[crnt]) {
for (int v : routes[r]) {
if (v == target) return lvl;
q.push(v);
}
routes[r].clear();
}
adj[crnt].clear();
}
}
return -1;
}
};

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

@@ -288,6 +288,7 @@ for solving problems.

| 0787 | Medium | [Cheapest Flights Within K Stops](Problems/0787.cpp) |
| 0797 | Medium | [All Paths From Source to Target](Problems/0797.cpp) |
| 0802 | Medium | [Find Eventual Safe States](Problems/0802.cpp) |
| 0815 | Hard | [Bus Routes](Problems/0815.cpp) |
| 0830 | Medium | [Kth Smallest Element in a BST](Problems/0230.cpp) |
| 0841 | Medium | [Keys and Rooms](Problems/0841.cpp) |
| 0844 | Easy | [Backspace String Compare](Problems/0844.cpp) |