Larry's notes

Merge Sort

• 功能：將兩個排序好的陣列合併成一個。

vector<int> merge(vector<int>& v1, vector<int>& v2)
{   // v1, v2 為由小到大排序後的陣列
    int n1 = v1.size(), n2 = v2.size();
    vector<int> v(n1 + n2);
    int i = 0, i1 = 0, i2 = 0;
    while (i1 < n1 || i2 < n2)
    {
        if (i1 >= n1) v[i++] = v2[i2++];
        else if (i2 >= n2) v[i++] = v1[i1++];
        else v[i++] = v1[i1] < v2[i2] ? v1[i1++] : v2[i2++];
    }
    return v;
}

Split

• 功能：Implement Python 的 split() 函式

vector<string> split(string& str, char& sign)
{
    vector<string> v;
    size_t idx = 0;
    size_t pos;

    while ((pos = str.find(sign, idx)) != string::npos)
    {
        v.push_back(str.substr(idx, pos - idx));
        idx = pos + 1;
    }
    if (idx < str.size()) v.push_back(str.substr(idx));

    return v;
}