day 5, challange 2

5th_day/2/example.txt

@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32

5th_day/2/main.cpp

@@ -0,0 +1,75 @@
+#include <algorithm>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <vector>
+
+using namespace std;
+
+struct Range {
+  long long begining;
+  long long end;
+};
+
+vector<string> read_file(const string &FILE_NAME) {
+  ifstream file(FILE_NAME);
+  string s;
+
+  vector<string> result;
+
+  while (getline(file, s)) {
+    result.push_back(s);
+  }
+  return result;
+}
+
+vector<Range> get_fresh_ids(const vector<string> input) {
+  vector<Range> fresh_ids;
+  for (string line : input) {
+    if (line.empty()) {
+      break;
+    }
+    string begining, end;
+    begining = line.substr(0, line.find("-"));
+    end = line.substr(line.find("-") + 1);
+    Range l_range = {stoll(begining), stoll(end)};
+    fresh_ids.push_back(l_range);
+  }
+
+  return fresh_ids;
+}
+
+bool compareRanges(const Range &a, const Range &b) {
+  return a.begining < b.begining;
+}
+
+int main() {
+  const string FILE_NAME = "input.txt";
+
+  vector<string> input = read_file(FILE_NAME);
+  vector<Range> fresh_ids = get_fresh_ids(input);
+  long long count = 0;
+
+  sort(fresh_ids.begin(), fresh_ids.end(), compareRanges);
+
+  vector<Range> merged_fresh_ids;
+  merged_fresh_ids.push_back(fresh_ids[0]);
+
+  for (int i = 1; i < fresh_ids.size(); i++) {
+    Range current_range = fresh_ids[i];
+    Range &last_range = merged_fresh_ids.back();
+
+    if (current_range.begining <= last_range.end + 1) {
+      last_range.end = max(last_range.end, current_range.end);
+    } else {
+      merged_fresh_ids.push_back(current_range);
+    }
+  }
+
+  for (Range range : merged_fresh_ids) {
+    count += range.end - range.begining + 1;
+  }
+
+  cout << count;
+  return 0;
+}