Added my solutions to todays programming introduction exam

3 files changed, 206 insertions, 0 deletions

diff --git a/Year 1/Programming introduction/Exams/Exam1/prob1.cpp b/Year 1/Programming introduction/Exams/Exam1/prob1.cpp
new file mode 100644
index 0000000..541c60c
--- /dev/null
+++ b/Year 1/Programming introduction/Exams/Exam1/prob1.cpp
@@ -0,0 +1,45 @@
+#include <iostream>
+
+using namespace std;
+
+bool canConcatNumber(unsigned int N, unsigned int K) {
+	if (N < 100) return false;
+
+	/* Get middle digits (which are reversed) */
+
+	unsigned int middleN = 1; // using 1 for cases where we have zeroes between our end digits, like in 1002001
+	for (unsigned int i = 0; N != 0; i++) {
+		if (i > 0 && N > 9)
+			(middleN *= 10) += N % 10;
+		N /= 10;
+	}
+
+	/* Get width of K as a power of 10 and reverse K */
+
+	unsigned int kWidth = 1, revK = 0;
+	for (unsigned int tmpK = K; tmpK != 0; kWidth *= 10) {
+		(revK *= 10) += tmpK % 10;
+		tmpK /= 10;
+	}
+
+	/* Check if revK is inside middleN */
+
+	while (middleN != 1) {
+		if ((middleN - revK) % kWidth == 0)
+			return true;
+		middleN /= 10;
+	}
+
+	return false;
+}
+
+int main() {
+	cout << "N = ";
+	int N;
+	cin >> N;
+	cout << "K = ";
+	int K;
+	cin >> K;
+
+	cout << (canConcatNumber(N, K) ? "True" : "False") << endl;
+}
diff --git a/Year 1/Programming introduction/Exams/Exam1/prob2.cpp b/Year 1/Programming introduction/Exams/Exam1/prob2.cpp
new file mode 100644
index 0000000..c941112
--- /dev/null
+++ b/Year 1/Programming introduction/Exams/Exam1/prob2.cpp
@@ -0,0 +1,47 @@
+#include <iostream>
+
+using namespace std;
+
+bool isNeighbourNum(int n) {
+	while (n != 0) {
+		if (n % 10 == (n / 10) % 10)
+			return false;
+		n /= 10;
+	}
+	return true;
+}
+
+int subNeighbours(int a, int b) {
+	int smallest = 0, biggest = 0;
+
+	for (int i = a; i <= b; i++) {
+		if (isNeighbourNum(i)) {
+			if (i < smallest || !smallest)
+				smallest = i;
+			if (i > biggest || !biggest)
+				biggest = i;
+		}
+	}
+
+	if (!smallest || !biggest) {
+		return -1;
+	}
+
+	return biggest - smallest;
+}
+
+int main() {
+	cout << "a = ";
+	int a;
+	cin >> a;
+	cout << "b = ";
+	int b;
+	cin >> b;
+
+	int sub = subNeighbours(a, b);
+
+	if (sub == -1)
+		cout << "No adjacent numbers!" << endl;
+	else
+		cout << sub << endl;
+}
diff --git a/Year 1/Programming introduction/Exams/Exam1/prob3.cpp b/Year 1/Programming introduction/Exams/Exam1/prob3.cpp
new file mode 100644
index 0000000..07a21f2
--- /dev/null
+++ b/Year 1/Programming introduction/Exams/Exam1/prob3.cpp
@@ -0,0 +1,114 @@
+#include <iostream>
+
+using namespace std;
+
+const int MAX_SIZE = 1024;
+
+int deletedFromStartToSubset(char src[], int srcLen, char toCheck[], int toCheckLen) {
+	for (int i = 0, j = 0; i <= srcLen - toCheckLen; i++) {
+		/* Check if values from toCheck correspond to those of src with offset */
+
+		for (j = 0; j < toCheckLen; j++) {
+			if (src[j + i] != toCheck[j])
+				break;
+		}
+
+		if (j == toCheckLen)
+			return i;
+	}
+	return -1;
+}
+
+int deletedAndRotationIsSubset(char src[], int srcLen, char toCheck[], int toCheckLen) {
+	for (int rot = 0; rot < toCheckLen; rot++) {
+		/* Check if subset */
+
+		int deleted = deletedFromStartToSubset(src, srcLen, toCheck, toCheckLen);
+		if (deleted >= 0)
+			return deleted;
+
+		/* Rotate toCheck */
+
+		char lastVal = toCheck[toCheckLen - 1];
+		for (int i = toCheckLen - 2; i >= 0; i--) {
+			toCheck[i + 1] = toCheck[i];
+		}
+		toCheck[0] = lastVal;
+	}
+	return -1;
+}
+
+/* Bonus */
+
+int validRotationByDelSrc(char src[], int srcLen, char toCheck[], int toCheckLen, int deletedIndexes[]) {
+	char common[MAX_SIZE];
+
+	int di = 1;
+	for (int i = 0, ci = 0; i < srcLen; i++) {
+		for (int j = 0; j < toCheckLen; j++) {
+			if (src[i] == toCheck[j]) {
+				common[ci++] = toCheck[j];
+				deletedIndexes[di++] = i; // I know this is wrong, but I didn't have time to fix it :D
+				break;
+			}
+		}
+	}
+	deletedIndexes[0] = di; // Length at position 0
+
+	return deletedAndRotationIsSubset(common, toCheckLen, toCheck, toCheckLen);
+}
+
+int main() {
+
+
+	/* Get input */
+
+	cout << "size1: ";
+	int size1;
+	cin >> size1;
+	cout << "size2: ";
+	int size2;
+	cin >> size2;
+
+	cout << "firstArr: ";
+	char firstArr[MAX_SIZE];
+	for (int i = 0; i < size1; i++)
+		cin >> firstArr[i];
+
+	cout << "secondArr: ";
+	char secondArr[MAX_SIZE];
+	for (int i = 0; i < size2; i++)
+		cin >> secondArr[i];
+
+	/* Output result */
+
+	int deleted = deletedAndRotationIsSubset(firstArr, size1, secondArr, size2);
+
+	if (deleted == -1) {
+		int deletedIndexes[MAX_SIZE];
+		deleted = validRotationByDelSrc(firstArr, size1, secondArr, size2, deletedIndexes);
+
+		if (deleted == -1)
+			cout << "No rotations found!" << endl;
+		else {
+			cout << "Rotation \"";
+
+			for (int i = 0; i < size2; i++)
+				cout << secondArr[i];
+
+			cout << "\" found after deleting characters: ";
+
+			for (int i = 1; i < deletedIndexes[0]; i++)
+				cout << deletedIndexes[i] << " ";
+			cout << endl;
+		}
+	}
+	else {
+		cout << "Rotation \"";
+
+		for (int i = 0; i < size2; i++)
+			cout << secondArr[i];
+
+		cout << "\" found after deleting " << deleted << " characters from the start and " << (size1 - size2 - deleted) << " characters from the end." << endl;
+	}
+}