Merge pull request #60 from PawanJaiswal0843/master

392.is-subsequence.cpp

Author: PawanJaiswal08

392.is-subsequence.cpp

@@ -0,0 +1,63 @@
+// 392. Is Subsequence
+#include<bits/stdc++.h>
+using namespace std;
+
+void solve(string &t, vector<string> &ans, int index, string &temp) {
+
+    if(index == t.size()) {
+        ans.push_back(temp);
+        return;
+    }
+
+    // exclude
+    solve(t, ans, index+1, temp);
+
+    // inclusion
+    temp.push_back(t[index]);
+    solve(t, ans, index+1, temp);
+    temp.pop_back();
+}
+
+bool isSubsequence(string s, string t) {
+
+    vector<string> ans;
+    string temp = "";
+
+    solve(t, ans, 0, temp);
+    
+    for(int i=0; i<ans.size(); i++) {
+        if(ans[i] == s) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool solve2(string s, string t, int i, int j) {
+
+    if(i >= s.size())
+        return true;
+
+    if(i < s.size() && j >= t.size())
+        return false;
+
+    if(s[i] == t[j])
+        return solve(s, t, i+1, j+1);
+        
+    else
+        return solve(s, t, i, j+1);
+}
+
+bool isSubsequence1(string s, string t) {
+    return solve2(s, t, 0, 0);
+}
+int main() {
+
+    string s = "abc";
+    string t = "ahbgdc";
+
+    cout << isSubsequence(s, t);
+
+    return 0;
+}