LeetCode-Maximal Rectangle[code]
code:
1 #include <iostream> 2 #include <vector> 3 #include <stack> 4 #include <algorithm> 5 using namespace std; 6 7 class Solution { 8 public: 9 int largestRectangleArea(vector<int> &height) { 10 height.push_back(0); 11 int i = 0; 12 int result = 0; 13 stack<int> s; 14 while (i < height.size()) 15 { 16 if (s.empty() || height[i]>height[s.top()]) 17 s.push(i++); 18 else 19 { 20 int tmp = s.top(); 21 s.pop(); 22 result = max(result, height[tmp] * (s.empty() ? i : i - s.top() - 1)); 23 } 24 } 25 return result; 26 } 27 28 int maximalRectangle(vector<vector<char> > &matrix) { 29 if (matrix.size() == 0 || matrix[0].size() == 0) return 0; 30 int H = matrix.size(), W = matrix[0].size(); 31 int ret = 0; 32 33 int **tmpHeight = new int*[H]; 34 for (int i = 0; i < H; i++) 35 { 36 tmpHeight[i] = new int[W]; 37 } 38 39 for (int i = 0; i < H; i++) 40 { 41 for (int j = 0; j < W; j++) 42 { 43 if (matrix[i][j] == '0') 44 { 45 tmpHeight[i][j] = 0; 46 } 47 else 48 { 49 50 tmpHeight[i][j] = (i == 0 ? 1 : tmpHeight[i - 1][j] + 1); 51 } 52 } 53 } 54 for (int i = 0; i < H; i++) 55 { 56 vector<int> vtmp(tmpHeight[i], tmpHeight[i] + W); 57 ret = max(ret, largestRectangleArea(vtmp)); 58 } 59 return ret; 60 } 61 }; 62 63 int main() 64 { 65 vector<vector<char>> v; 66 67 char a1[] = { '0', '1', '0', '1', '1'}; 68 char a2[] = { '0', '1', '1', '1', '0' };//要用'1'和'0'来赋值！因为是char数组！不能用1,0 ! 69 char a3[] = { '1', '1', '1', '1','1' }; 70 v.push_back(vector<char>(a1, a1 + 5)); 71 v.push_back(vector<char>(a2, a2 + 5)); 72 v.push_back(vector<char>(a3, a3 + 5)); 73 Solution s; 74 cout << s.maximalRectangle(v) << endl; 75 return 0; 76 }
