Distinct Palindrome Substring

C++/Matrix Probability.cpp

@@ -0,0 +1,67 @@
+/// C++ program to find the probability  
+// that we do not cross boundary of a  
+// matrix after N moves. 
+#include <bits/stdc++.h> 
+using namespace std; 
+
+// check if (x, y) is valid matrix coordinate 
+bool isSafe(int x, int y, int m, int n) 
+{ 
+    return (x >= 0 && x < m &&  
+            y >= 0 && y < n); 
+} 
+
+// Function to calculate probability  
+// that after N moves from a given  
+// position (x, y) in m x n matrix,  
+// boundaries of the matrix will not be crossed. 
+double findProbability(int m, int n, int x,  
+                       int y, int N) 
+{ 
+    // boundary crossed 
+    if (!isSafe(x, y, m, n)) 
+        return 0.0; 
+
+    // N steps taken 
+    if (N == 0) 
+        return 1.0; 
+
+    // Initialize result 
+    double prob = 0.0; 
+
+    // move up 
+    prob += findProbability(m, n, x - 1,  
+                            y, N - 1) * 0.25; 
+
+    // move right 
+    prob += findProbability(m, n, x,  
+                            y + 1, N - 1) * 0.25; 
+
+    // move down 
+    prob += findProbability(m, n, x + 1, 
+                            y, N - 1) * 0.25; 
+
+    // move left 
+    prob += findProbability(m, n, x,  
+                            y - 1, N - 1) * 0.25; 
+
+    return prob; 
+} 
+
+// Driver code 
+int main() 
+{ 
+    // matrix size 
+    int m = 5, n = 5; 
+
+    // coordinates of starting point 
+    int i = 1, j = 1; 
+
+    // Number of steps 
+    int N = 2; 
+
+    cout << "Probability is "
+        << findProbability(m, n, i, j, N); 
+
+    return 0; 
+} 

C++/distinct palindrome sub-strings.cpp

@@ -0,0 +1,75 @@
+// C++ program to find all distinct palindrome sub-strings 
+// of a given string 
+#include <iostream> 
+#include <map> 
+using namespace std; 
+
+// Function to print all distinct palindrome sub-strings of s 
+void palindromeSubStrs(string s) 
+{ 
+    map<string, int> m; 
+    int n = s.size(); 
+
+    // table for storing results (2 rows for odd- 
+    // and even-length palindromes 
+    int R[2][n+1]; 
+
+    // Find all sub-string palindromes from the given input 
+    // string insert 'guards' to iterate easily over s 
+    s = "@" + s + "#"; 
+
+    for (int j = 0; j <= 1; j++) 
+    { 
+        int rp = 0;   // length of 'palindrome radius' 
+        R[j][0] = 0; 
+
+        int i = 1; 
+        while (i <= n) 
+        { 
+            //  Attempt to expand palindrome centered at i 
+            while (s[i - rp - 1] == s[i + j + rp]) 
+                rp++;  // Incrementing the length of palindromic 
+                       // radius as and when we find vaid palindrome 
+
+            // Assigning the found palindromic length to odd/even 
+            // length array 
+            R[j][i] = rp; 
+            int k = 1; 
+            while ((R[j][i - k] != rp - k) && (k < rp)) 
+            { 
+                R[j][i + k] = min(R[j][i - k],rp - k); 
+                k++; 
+            } 
+            rp = max(rp - k,0); 
+            i += k; 
+        } 
+    } 
+
+    // remove 'guards' 
+    s = s.substr(1, n); 
+
+    // Put all obtained palindromes in a hash map to 
+    // find only distinct palindromess 
+    m[string(1, s[0])]=1; 
+    for (int i = 1; i <= n; i++) 
+    { 
+        for (int j = 0; j <= 1; j++) 
+            for (int rp = R[j][i]; rp > 0; rp--) 
+               m[s.substr(i - rp - 1, 2 * rp + j)]=1; 
+        m[string(1, s[i])]=1; 
+    } 
+
+    //printing all distinct palindromes from hash map 
+   cout << "Below are " << m.size()-1 
+        << " palindrome sub-strings"; 
+   map<string, int>::iterator ii; 
+   for (ii = m.begin(); ii!=m.end(); ++ii) 
+      cout << (*ii).first << endl; 
+} 
+
+// Driver program 
+int main() 
+{ 
+    palindromeSubStrs("abaaa"); 
+    return 0; 
+}