longest-absolute-file-path.cpp

/*
 * Copyright (c) 2018 Christopher Friedt
 *
 * SPDX-License-Identifier: MIT
 */

#include <string>
#include <vector>

using namespace std;

// https://leetcode.com/problems/longest-absolute-file-path/

class Solution {
public:
  int lengthLongestPath(string input) {

    int lngst = 0;
    bool file = false;
    vector<int> plen({0});
    vector<string> ppath({""});
    int len = 0;
    vector<int> depth({0});
    string path;

    for (size_t i = 0; i < input.size(); ++i) {
      char ch = input[i];
      switch (ch) {
      case '.':
        file = true;
        len++;
        // path += ch;
        break;
      case '\n': {
        int new_depth = 0;
        for (size_t j = i + 1; j < input.size() && '\t' == input[j];
             j++, new_depth++)
          ;
        for (; depth.back() > new_depth;) {
          depth.pop_back();
          plen.pop_back();
          // ppath.pop_back();
        }
        if (new_depth > depth.back()) {
          depth.push_back(new_depth);
          plen.push_back(1 + len);
          // ppath.push_back( ppath.back() + "/" + path );
          len = plen.back();
        } else {
          len = plen.back();
        }
        i += new_depth;
        // path = "";
        file = false;
        break;
      }
      default:
        len++;
        // path += ch;
        break;
      }
      if (file) {
        lngst = max(len, lngst);
      }
    }
    return lngst;
  }
};