Longest Common Subsequence C++ Solution

Hacker rank Problem Solving/LongestCommonSubsequence.cpp

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+#include <bits/stdc++.h>
+
+using namespace std;
+
+vector<string> split_string(string);
+
+// Complete the longestCommonSubsequence function below.
+vector<int> longestCommonSubsequence(vector<int> a, vector<int> b) {
+    int n,m;
+    //cin>>n>>m;
+    //int a[n],b[m];
+    // for(int i=0;i<n;i++)
+    //     cin>>a[i];
+    // for(int i=0;i<m;i++)
+    //     cin>>b[i];
+    n = a.size();
+    m = b.size();
+    int dp[n+1][m+1];
+    for(int i=0;i<=m;i++)
+        dp[0][i]=0;
+    for(int i=0;i<=n;i++)
+        dp[i][0]=0;
+    //dp[0][0]=0;
+    for(int i=1;i<=n;i++){
+        for(int j=1;j<=m;j++){
+            if(a[i-1]==b[j-1]){
+                dp[i][j] = dp[i-1][j-1]+1;
+            }
+            else{
+                dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
+            }
+        }
+    }
+    // for(int i=0;i<=n;i++){
+    //     for(int j=0;j<=m;j++)
+    //         cout<<dp[i][j]<<" ";
+    //     cout<<endl;
+    // }
+    int arr[dp[n][m]];
+    int k=0;
+    //for(int i=n;i>=0;i--){
+    int i=n;
+        for(int j=m;j>0;){
+            //cout<<i<<" "<<j<<"!!";
+            if(dp[i][j]==dp[i][j-1]){
+                j--;
+                continue;
+            }
+            else if(dp[i][j]==dp[i-1][j])
+                i--;
+            else{
+                arr[k++] = a[i-1];
+                i--;
+                j--;
+            }
+        }
+    //}
+    vector<int>ret;
+    for(int i=dp[n][m]-1;i>=0;i--)
+        ret.push_back(arr[i]);
+    //cout<<endl;
+    return ret;
+
+}
+
+int main()
+{
+    ofstream fout(getenv("OUTPUT_PATH"));
+
+    string nm_temp;
+    getline(cin, nm_temp);
+
+    vector<string> nm = split_string(nm_temp);
+
+    int n = stoi(nm[0]);
+
+    int m = stoi(nm[1]);
+
+    string a_temp_temp;
+    getline(cin, a_temp_temp);
+
+    vector<string> a_temp = split_string(a_temp_temp);
+
+    vector<int> a(n);
+
+    for (int i = 0; i < n; i++) {
+        int a_item = stoi(a_temp[i]);
+
+        a[i] = a_item;
+    }
+
+    string b_temp_temp;
+    getline(cin, b_temp_temp);
+
+    vector<string> b_temp = split_string(b_temp_temp);
+
+    vector<int> b(m);
+
+    for (int i = 0; i < m; i++) {
+        int b_item = stoi(b_temp[i]);
+
+        b[i] = b_item;
+    }
+
+    vector<int> result = longestCommonSubsequence(a, b);
+
+    for (int i = 0; i < result.size(); i++) {
+        fout << result[i];
+
+        if (i != result.size() - 1) {
+            fout << " ";
+        }
+    }
+
+    fout << "\n";
+
+    fout.close();
+
+    return 0;
+}
+
+vector<string> split_string(string input_string) {
+    string::iterator new_end = unique(input_string.begin(), input_string.end(), [] (const char &x, const char &y) {
+        return x == y and x == ' ';
+    });
+
+    input_string.erase(new_end, input_string.end());
+
+    while (input_string[input_string.length() - 1] == ' ') {
+        input_string.pop_back();
+    }
+
+    vector<string> splits;
+    char delimiter = ' ';
+
+    size_t i = 0;
+    size_t pos = input_string.find(delimiter);
+
+    while (pos != string::npos) {
+        splits.push_back(input_string.substr(i, pos - i));
+
+        i = pos + 1;
+        pos = input_string.find(delimiter, i);
+    }
+
+    splits.push_back(input_string.substr(i, min(pos, input_string.length()) - i + 1));
+
+    return splits;
+}