feat: updated LCS problem

longest-common-subsequence/src/checker.cpp

@@ -3,15 +3,48 @@
 
 using namespace std;
 
+bool isSubsequence(string &original, string &sub) {
+    int j = 0;
+    for (int i = 0; i < original.size() && j < sub.size(); i++) {
+        if (original[i] == sub[j]) j++;
+    }
+    return j == sub.size();
+}
+
+int readAns(InStream &stream, string &s1, string &s2) {
+    int ans = stream.readInt(0, min(s1.size(), s2.size()), "Common subsequence length");
+    stream.readEoln();
+    string subsequence;
+    if (ans == 0) {
+        stream.readEoln();
+        subsequence = "";
+    } else {
+        subsequence = stream.readToken("[a-z]+");
+        stream.readEoln();
+    }
+    stream.readEof();
+    
+    quitif(subsequence.size() != ans, _wa, "sequence has length different from informed");
+    quitif(!isSubsequence(s1, subsequence), _wa, "%s is not a subsequence of %s", subsequence, s1);
+    quitif(!isSubsequence(s2, subsequence), _wa, "%s is not a subsequence of %s", subsequence, s2);
+
+    return ans;
+}
+
 int main(int argc, char* argv[]) {
-    setName("compare two signed int%d's", 8 * int(sizeof(int)));
+    setName("compare two signed int%d's and check if subsequence given is valid", 8 * int(sizeof(int)));
     registerTestlibCmd(argc, argv);
 
-    int ja = ans.readInt();
-    int pa = ouf.readInt();
+    int n = inf.readInt(), m = inf.readInt();
+    string s1 = inf.readToken(), s2 = inf.readToken();
 
-    if (ja != pa)
-        quitf(_wa, "expected %d, found %d", ja, pa);
+    int ja = readAns(ans, s1, s2);
+    int pa = readAns(ouf, s1, s2);
 
-    quitf(_ok, "all answers are correct");
+    if (ja > pa)
+        quitf(_wa, "jury has the better answer: jans = %d, pans = %d\n", ja, pa);
+    else if (ja < pa)
+        quitf(_fail, "participant has the better answer: jans = %d, pans = %d\n", ja, pa);
+
+    quitf(_ok, "answer is correct");
 }