cpp: add «739. Daily Temperatures»

Signed-off-by: Matej Focko <me@mfocko.xyz>

cpp/daily-temperatures.cpp

@@ -0,0 +1,34 @@
+#include <cassert>
+#include <vector>
+
+class Solution {
+  public:
+    std::vector<int> dailyTemperatures(const std::vector<int> &temperatures) {
+        std::vector<int> result(temperatures.size(), 0);
+        std::vector<int> st;
+
+        for (auto i = 0u; i < temperatures.size(); ++i) {
+            while (!st.empty() && temperatures[st.back()] < temperatures[i]) {
+                result[st.back()] = i - st.back();
+                st.pop_back();
+            }
+
+            st.push_back(i);
+        }
+
+        return result;
+    }
+};
+
+int main() {
+    Solution s;
+
+    assert((s.dailyTemperatures(std::vector{73, 74, 75, 71, 69, 72, 76, 73}) ==
+            std::vector{1, 1, 4, 2, 1, 1, 0, 0}));
+    assert((s.dailyTemperatures(std::vector{30, 40, 50, 60}) ==
+            std::vector{1, 1, 1, 0}));
+    assert(
+        (s.dailyTemperatures(std::vector{30, 60, 90}) == std::vector{1, 1, 0}));
+
+    return 0;
+}