c++ solution for challenge 74 task 2

1 files changed, 39 insertions, 0 deletions

diff --git a/challenge-074/walt-mankowski/cpp/ch-2.cpp b/challenge-074/walt-mankowski/cpp/ch-2.cpp
new file mode 100644
index 0000000000..dc94578e19
--- /dev/null
+++ b/challenge-074/walt-mankowski/cpp/ch-2.cpp
@@ -0,0 +1,39 @@
+#include <string.h>
+#include <iostream>
+#include <set>
+#include <list>
+
+using namespace std;
+
+int main(int argc, char *argv[]) {
+    const char *s = argv[1];
+    set<char> seen;
+    list<char> nr;
+    char *out = new char[strlen(s)+1];
+    out[strlen(s)] = '\0';
+
+    for (size_t i = 0; i < strlen(s); i++) {
+        const char c = s[i];
+        
+        // have we seen c before?
+        if (seen.find(c) == seen.end()) {
+            seen.insert(c);
+            nr.push_back(c);
+        } else {
+            // remove c from nr
+            for (auto x = nr.begin(); x != nr.end(); x++)
+                if (*x == c) {
+                    nr.erase(x);
+                    break;
+                }
+        }
+
+        if (nr.empty()) 
+            out[i] = '#';
+        else {
+            auto p = *(nr.crbegin());
+            out[i] = p;
+        }
+    }
+    cout << out << endl;                
+}