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| 1 | +// 区间离散化解法(低效 120ms) |
| 2 | +class Solution { |
| 3 | +public: |
| 4 | + vector<pair<int, int>> getSkyline(vector<vector<int>>& buildings) { |
| 5 | + set<int> poss ; |
| 6 | + map<int, int> m ; |
| 7 | + for (auto v: buildings) |
| 8 | + { |
| 9 | + poss.insert(v[0]) ; |
| 10 | + poss.insert(v[1]) ; |
| 11 | + } |
| 12 | + |
| 13 | + int i = 0 ; |
| 14 | + for (int pos: poss) |
| 15 | + m.insert(pair<int, int>(pos, i++)) ; |
| 16 | + |
| 17 | + vector<int> highs(m.size(), 0) ; |
| 18 | + for (auto v: buildings) |
| 19 | + { |
| 20 | + const int b = m[v[0]], e = m[v[1]] ; |
| 21 | + for (int i = b; i < e; ++i) |
| 22 | + highs[i] = max(highs[i], v[2]) ; |
| 23 | + } |
| 24 | + |
| 25 | + vector<pair<int, int>> res ; |
| 26 | + vector<int> mm(poss.begin(), poss.end()) ; |
| 27 | + for (int i = 0; i < highs.size(); ++i) |
| 28 | + { |
| 29 | + if (highs[i] != highs[i+1]) |
| 30 | + res.push_back(pair<int, int>(mm[i], highs[i])) ; |
| 31 | + else |
| 32 | + { |
| 33 | + const int start = i ; |
| 34 | + res.push_back(pair<int, int>(mm[start], highs[i])) ; |
| 35 | + while (highs[i] == highs[i+1]) |
| 36 | + ++i ; |
| 37 | + } |
| 38 | + } |
| 39 | + return res ; |
| 40 | + } |
| 41 | +}; |
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