Added Week3 p1 and p2

Author: Linh Chu

Week 3/week3_problem1.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int main() {
+    int N;
+    int Q;
+    int cc = 0;
+    while(cin >> N && ++cc) {
+        cin >> Q;
+        vector<int> data(N);
+        for(int i = 0; i < N; i++) {
+            cin >> data[i];
+        }
+        if (!Q)
+            continue;
+        sort(data.begin(), data.end());
+        cout << "CASE# " << cc << ":\n";
+        for (int i = 0; i < Q; i++) {
+            int q;
+            cin >> q;
+            auto it = lower_bound(data.begin(), data.end(), q);
+            if (*it == q)
+                cout << q << " found at " << it - data.begin() + 1 << '\n';
+            else
+                cout << q << " not found\n";
+        }
+    }
+}

Week 3/week3_problem2.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+public:
+    bool searchMatrix(vector<vector<int>>& matrix, int target) {
+        int N, M;
+        if (matrix.size() == 0) return false;
+        N = matrix.size();
+        M = matrix[0].size();
+        long long low, high;
+        low = 0; high = N * M - 1;
+
+        while (low <= high) {
+            long long mid = (low + high) / 2;
+            if (matrix[mid/M][mid%M] == target) return true;
+            else if (matrix[mid/M][mid%M] < target) {
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+        }
+
+        return false;
+    }
+};
+
+
+int main(){
+    int N, M;
+    cin >> N >> M;
+    vector<vector<int> > table(N);
+    for (int i = 0; i < N; i++){
+        table[i].resize(M);
+        for (int j = 0; j < M; j++) {
+            cin >> table[i][j];
+        }
+    }
+    int t;
+    cin >> t;
+    Solution solution;
+    cout << solution.searchMatrix(table, t) << '\n';
+}
+
+