leetcode-daily/cpp/2205/220525.cpp

30 lines
1.0 KiB
C++

#include <vector>
#include <algorithm>
/**
* 354. Russian Doll Envelopes
* You are given a 2D array of integers envelopes where envelopes[i] = [wi, hi] represents the width and the height of an envelope.
* One envelope can fit into another if and only if both the width and height of one envelope are greater than the other envelope's width and height.
* Return the maximum number of envelopes you can Russian doll (i.e., put one inside the other).
* Note: You cannot rotate an envelope.
*/
class Solution {
public:
static int maxEnvelopes(std::vector<std::vector<int>>& e) {
std::sort(e.begin(), e.end(), [](const std::vector<int>& x, const std::vector<int>& y) {
return (x[0] == y[0]) ? (x[1] > y[1]) : (x[0] < y[0]);
});
std::vector<int> ans;
std::for_each(e.begin(), e.end(), [&](const std::vector<int>& x) {
// Put this into list
int idx = std::lower_bound(ans.begin(), ans.end(), x[1]) - ans.begin();
if (idx >= ans.size())
ans.push_back(x[1]);
else
ans[idx] = x[1];
});
return ans.size();
}
};