写在前面
一共四题，1题easy，2题medium，1题hard
第一道，简单的系统设计题，要清楚object function；
第二道，同样应用题，但是通过率不高；
第三道，给出制定行和&列和的矩阵；
第四道，
- Design Parking System
- Alert Using Same Key-Card Three or More Times in a One Hour Period
- Find Valid Matrix Given Row and Column Sums
- Find Servers That Handled Most Number of Requests
Design Parking System
原题链接
解法：
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| class ParkingSystem {
public:
vector<int>ps;
ParkingSystem(int big, int medium, int small) {
ps.push_back(big);
ps.push_back(medium);
ps.push_back(small);
}
bool addCar(int carType) {
if(ps[carType-1]>0){
ps[carType-1]--;
return true;
}
else return false;
}
};
|
Alert Using Same Key-Card Three or More Times in a One Hour Period
原题链接
解法：
Find Valid Matrix Given Row and Column Sums
原题链接
解法：Greedy
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| class Solution {
public:
vector<vector<int>> restoreMatrix(vector<int>& row, vector<int>& col) {
int m = row.size(), n = col.size();
vector<vector<int>> A(m, vector<int>(n, 0));
for (int i = 0; i < m; ++i) {
for (int j = 0 ; j < n; ++j) {
A[i][j] = min(row[i], col[j]);
row[i] -= A[i][j];
col[j] -= A[i][j];
}
}
return A;
}
};
|
Time: O(mn)
Space: O(mn)
Find Servers That Handled Most Number of Requests
原题链接