Description

Submission

• Vector constructor
• Subvector
• Vector concatenation
• The insertion should be at res.end() instead of prev(res.end())

#include <bits/stdc++.h>

using namespace std;

vector<string> split_string(string);

// Complete the rotLeft function below.
vector<int> rotLeft(vector<int> a, int d) {
    d = d % a.size();
    vector<int> res(a.begin() + d, a.end());
    res.insert(res.end(), a.begin(), a.begin() + d);
    return res;
}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    string nd_temp;
    getline(cin, nd_temp);

    vector<string> nd = split_string(nd_temp);

    int n = stoi(nd[0]);

    int d = stoi(nd[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;
    }

    vector<int> result = rotLeft(a, d);

    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;
}

References

1. https://stackoverflow.com/questions/201718/concatenating-two-stdvectors
2. https://stackoverflow.com/questions/421573/best-way-to-extract-a-subvector-from-a-vector
3. http://www.cplusplus.com/reference/vector/vector/insert/