local

Author: mostafa-saad

18-Programming-4kids/11_homework_1_answer_TODO_1-7.cpp

@@ -0,0 +1,29 @@
+// By Basel Bairkdar: https://www.facebook.com/baselbairkdar
+#include<iostream>
+using namespace std;
+
+string input,str;
+
+int main()
+{
+    cin >> input >> str;
+    bool is_prefix=1; /** we will say that it's prefix at the beginning **/
+    int n=str.size();
+    /**
+        check if str is eqaul
+        to the first n letter of input
+    **/
+    for (int i=0;i<n;i++)
+    {
+        if (input[i]!=str[i])
+        {
+            is_prefix=0;
+            break;
+        }
+    }
+    if (is_prefix)
+        cout << "YES\n";
+    else
+        cout << "NO\n";
+    return 0;
+}

18-Programming-4kids/11_homework_2_answer.cpp

@@ -0,0 +1,34 @@
+// By Basel Bairkdar: https://www.facebook.com/baselbairkdar
+#include<iostream>
+using namespace std;
+
+string input,str;
+
+int main()
+{
+    cin >> input >> str;
+    bool is_suffix=1; /** we will say that it's suffix at the beginning **/
+    int n=str.size();
+    /**
+        check if str is equal
+        to the last n letter of input
+    **/
+    int in=0; /** index of str **/
+    for (int i=input.size()-n;i<input.size();i++)
+    {
+        if (input[i]==str[in])/** careful, str[in] not str[i] **/
+        {
+            in++;
+        }
+        else if (input[i]!=str[in])/** careful, str[in] not str[i] **/
+        {
+            is_suffix=0;
+            break;
+        }
+    }
+    if (is_suffix)
+        cout << "YES\n";
+    else
+        cout << "NO\n";
+    return 0;
+}

18-Programming-4kids/11_homework_3_answer.cpp

@@ -0,0 +1,42 @@
+// By Basel Bairkdar: https://www.facebook.com/baselbairkdar
+#include<iostream>
+using namespace std;
+
+string input,str;
+
+int main()
+{
+    cin >> input >> str;
+    bool is_substring=0; /** we will say that it's not a substring at the beginning **/
+
+
+    int in=0;
+    for (int i=0;i<input.size();i++)
+    {
+        if (input[i]==str[in])/** characters are equal (possible match) **/
+        {
+            in++; /** increase index **/
+            if (in==str.size())
+            {
+                is_substring=1;
+                break;/** found a solution, no need to stay in the loop **/
+            }
+        }
+        else
+        {
+            /**
+                if the characters are different and we have not broken
+                the loop yet (no solution so far)
+                make in=0 to look for possible match
+            **/
+            in=0;
+        }
+    }
+
+
+    if (is_substring)
+        cout << "YES\n";
+    else
+        cout << "NO\n";
+    return 0;
+}

18-Programming-4kids/11_homework_4_answer.cpp

@@ -0,0 +1,28 @@
+// By Basel Bairkdar: https://www.facebook.com/baselbairkdar
+#include<iostream>
+using namespace std;
+
+string input,str;
+
+int main()
+{
+    cin >> input >> str;
+
+    int in=0;/** index of str **/
+
+    for (int i=0;i<input.size();i++)
+    {
+        if (input[i]==str[in])/** if there is a match just increase the index **/
+        {
+            in++;
+            if (in==str.size())break;/** reached the end of str **/
+        }
+    }
+
+
+    if (in==str.size())/** have we reached the end of str ? if so then it is a subsequence **/
+        cout << "YES\n";
+    else
+        cout << "NO\n";
+    return 0;
+}

18-Programming-4kids/11_homework_5_answer.cpp

@@ -0,0 +1,30 @@
+// By Basel Bairkdar: https://www.facebook.com/baselbairkdar
+#include<iostream>
+using namespace std;
+
+int main()
+{
+    int ans=0;
+    string str;
+
+    cin >> str;
+    /**
+        how to convert str to int ?
+        say we have a string "123"
+        now, make ans=1 which is the first character of str
+        the second character is 2
+        we need to put 2 in the ans properly (so we get ans=12 for now)
+        simply, if we multiply ans by 10
+        ans*=10 => ans=10
+        then add 2 => ans+=2 => ans=12
+        repeat same process for every character
+    **/
+    for (int i=0;i<str.size();i++)
+    {
+        ans*=10;// when i=0 ans is 0 too, so ans*=10 keeps ans=0
+
+        ans+=str[i]-'0';/** when i=0 ans will be the first character of str **/
+    }
+    cout << ans << " " << ans*3 << endl;
+    return 0;
+}

18-Programming-4kids/11_homework_6_answer.cpp

@@ -0,0 +1,26 @@
+// By Mohamed Yasser https://www.facebook.com/SanfourRadwan
+#include <iostream>
+#include <string>
+using namespace std;
+int main()
+{
+    string input;
+    cin >> input;
+    int len = input.size();
+    /**
+        we sure that first character in string
+        is found in first group
+    **/
+    cout << input[0];
+    for(int i = 1 ; i < len ; i++){
+        /**
+            if the current character is equal previous character
+            then they are in same group
+            otherwise they are in Different groups
+        */
+        if(input[i-1] != input[i])/// print space between the different groups
+            cout << ' ';
+        cout << input[i];
+    }
+    return 0;
+}

18-Programming-4kids/11_homework_7_answer.cpp

@@ -0,0 +1,27 @@
+// By Mohamed Yasser https://www.facebook.com/SanfourRadwan
+
+#include <iostream>
+#include <string>
+using namespace std;
+int main()
+{
+    string input;
+    cin >> input;
+    int len = input.size() , cnt = 1;
+    for(int i = 1 ; i < len ; i++){
+        /**
+            if the current character is equal previous character
+            then they are in same group and we need increment count by 1
+
+            otherwise they are in Different groups and we need print last group
+            and start count 1
+        */
+        if(input[i-1] != input[i]){
+            cout << input[i-1] << cnt << "_";
+            cnt = 1;
+        }else cnt++;
+    }
+    /// print last group
+    cout << input[len-1] << cnt << "\n";
+    return 0;
+}

18-Programming-4kids/11_homework_8_answer.cpp

@@ -0,0 +1,36 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+	string a, b;
+
+	cin >> a >> b;
+
+	int sz = a.size();
+
+	if (sz < b.size())
+		sz = b.size();
+
+	int smaller = -1;
+
+	for (int i = 0; smaller == -1 && i < sz; ++i) {
+		if (a[i] != b[i]) {
+			if (a[i] < b[i])
+				smaller = 0;
+			else
+				smaller = 1;
+		}
+	}
+	if (smaller == -1) { // then the first letters are common. Small in length is smaller
+		if (a.size() <= b.size())
+			smaller = 0;
+		else
+			smaller = 1;
+	}
+	if (smaller == 0)
+		cout << "YES\n";
+	else
+		cout << "NO\n";
+
+	return 0;
+}

18-Programming-4kids/11_homework_9_answer.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+using namespace std;
+
+int main() {
+	string num;
+
+	// Guarantee input: must be 6 digits or more
+	cin >> num;
+
+	int sz = num.size();
+
+	int carry = 0;
+	for (int i = 0; i < sz; ++i) {
+		int digit = num[sz - 1 - i] - '0';
+
+		if (i < 4)
+			digit += 5;			// add 5 in first 4 times
+		digit += carry;		// add any carry
+
+		if (digit >= 10)
+			digit -= 10, carry = 1;
+		else
+			carry = 0;
+
+		num[sz - 1 - i] = digit + '0';
+	}
+	if(carry)
+		cout<<1;
+	cout << num;
+
+	return 0;
+}

18-Programming-4kids/11_homework_employees_v1.cpp renamed to 18-Programming-4kids/11_homework_9_answer_employees_v1.cpp

@@ -14,7 +14,7 @@ int main() {
 
 	while (true) {
 		int choice = -1;
-		cout << "Enter your choice:\n";
+		cout << "\nEnter your choice:\n";
 		cout << "1) Add new employee\n";
 		cout << "2) Print all employees\n";
 		cout << "3) Delete by age\n";
@@ -50,7 +50,7 @@ int main() {
 							<< " " << genders[i] << "\n";
 			}
 		} else if (choice == 3) {
-			cout << "Enter start and end age\n";
+			cout << "Enter start and end age: ";
 			int start, end;
 			cin >> start >> end;
 
@@ -59,7 +59,7 @@ int main() {
 					ages[i] = -1;// Let's mark a removed entry with -1 (lazy delete)
 			}
 		} else {
-			cout << "Enter the name and salary";
+			cout << "Enter the name and salary: ";
 			string name;
 			int salary;
 			cin >> name >> salary;