leetcode

Daily Problem

2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/ Problems/2306.cpp b/ Problems/2306.cpp

@@ -0,0 +1,44 @@

// Group by first letter, 637ms

class Solution {

public:

long long distinctNames(vector<string> &ideas) {

array<unordered_set<string>, 26> um;

for (const auto &idea : ideas)

um[idea.front() - 'a'].insert(idea.substr(1));

long long res = 0ll;

for (int i = 0; i < 26; i++) {

for (int j = i + 1; j < 26; j++) {

long long c1 = 0ll, c2 = 0ll;

for (const auto &s : um[i]) c1 += !um[j].count(s);

for (const auto &s : um[j]) c2 += !um[i].count(s);

res += c1 * c2;

}

}

return res * 2;

}

};

// Group by suffix, 373ms

class Solution {

public:

long long distinctNames(vector<string> &ideas) {

unordered_map<string, bitset<32>> um;

unordered_map<bitset<32>, int> cnt;

for (const auto &idea : ideas) um[idea.substr(1)].set(idea.front() - 'a');

for (const auto &[k, v] : um) cnt[v]++;

long long res = 0ll;

for (auto it1 = cnt.begin(); it1 != cnt.end(); it1++) {

for (auto it2 = next(it1); it2 != cnt.end(); it2++) {

int same = (it1->first & it2->first).count();

res += (it2->first.count() - same) * (it1->first.count() - same) *

it1->second * it2->second;

}

}

return res * 2;

}

};

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

@@ -397,6 +397,7 @@ for solving problems. | 2265 | Medium | [Count Nodes Equal to Average of Subtree](Problems/2265.cpp) | | 2279 | Medium | [Maximum Bags With Full Capacity of Rocks](Problems/2279.cpp) | | 2285 | Medium | [Maximum Total Importance of Roads](Problems/2285.cpp) |

| 2306 | Hard | [Naming a Company](Problems/2306.cpp) |

| 2316 | Medium | [Count Unreachable Pairs of Nodes in an Undirected Graph](Problems/2316.cpp) | | 2326 | Medium | [Spiral Matrix IV](Problems/2326.cpp) | | 2331 | Easy | [Evaluate Boolean Binary Tree](Problems/2331.cpp) |