Leetcode (#31)

* Add leetcode problem of the day

* Add leetcode problem of the day

leetcode/2418.cpp

@@ -0,0 +1,28 @@
+#include <algorithm>
+#include <numeric>
+#include <string>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+using std::string;
+using std::vector;
+
+vector<string> sort_strings_by_ints(vector<string> strings, vector<int> ints) {
+    vector<int> indices(ints.size());
+    std::iota(indices.begin(), indices.end(), 0);
+    std::ranges::stable_sort(indices,
+                             [&ints](int a, int b) {
+                                return ints[a] > ints[b]; });
+    vector<string> result(strings.size());
+    for (int i = 0; i < static_cast<int>(strings.size()); i++)
+        result[i] = strings[indices[i]];
+    return result; }
+
+TEST(sort_strings_by_ints, a) {
+    EXPECT_EQ((vector<string>{"foo", "bar", "baz"}),
+              sort_strings_by_ints({"bar", "foo", "baz"}, {1, 3, 1})); }
+
+int main(int argc, char **argv) {
+    testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS(); }

leetcode/885.cpp

@@ -0,0 +1,36 @@
+#include <map>
+#include <utility>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+using std::map;
+using std::pair;
+using std::vector;
+
+const map<char, char> next{{'E', 'S'}, {'S', 'W'}, {'W', 'N'}, {'N', 'E'}};
+
+const map<char, pair<int, int>> deltas{{'E', {0, +1}}, {'S', {+1, 0}}, {'W', {0, -1}}, {'N', {-1, 0}}};
+
+vector<vector<int>> spiral_matrix_iii(int rows, int cols, int rStart, int cStart) {
+    vector<vector<int>> ans{{rStart, cStart}};
+    int r = rStart, c = cStart;
+    int step = 1, i = 0;
+    char dir = 'E';
+    while (ans.size() < static_cast<uint64_t>(rows) * cols) {
+        const auto& [dr, dc]  = deltas.at(dir);
+        for (int i = 0; i < step; i++) {
+            r += dr;
+            c += dc;
+            if (0 <= r and r < rows and 0 <= c and c < cols) ans.push_back({r, c}); }
+        i++;
+        if (!(i % 2)) step++;
+        dir = next.at(dir); }
+    return ans; }
+
+TEST(spiral_matrix_iii, oversimple) {
+    EXPECT_EQ((vector<vector<int>>{{0, 0}, {0, 1}, {0, 2}, {0, 3}}), spiral_matrix_iii(1, 4, 0, 0)); }
+
+int main(int argc, char **argv) {
+    testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS(); }