130 lines
No EOL
4.5 KiB
C++
130 lines
No EOL
4.5 KiB
C++
#include <stdio.h>
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#include <list>
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#include <iostream>
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#include <fstream>
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#include <string>
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#include <vector>
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#include <sstream>
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#include <iterator>
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using namespace std;
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enum Direction {
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UP,
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DOWN,
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UNSET
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};
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int main(){
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string line;
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int safeReports = 0;
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stringstream wholeDoc;
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ifstream puzzle("input.txt", ifstream::in);
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while (getline(puzzle, line)) {
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istringstream lineStream(line);
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string numberString;
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list<int> currentLevels;
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while (getline(lineStream, numberString, ' ')) {
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int number = stoi(numberString);
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currentLevels.push_back(number);
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}
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list<int> currentLevelsBackup = currentLevels;
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int numOfLevelsProcessed = 0;
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auto curListIt = currentLevels.begin();
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curListIt++; //point to second item in list
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auto RevCurListIt = currentLevels.rbegin();
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RevCurListIt++; //points to second to last item
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enum Direction dir;
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bool listDirty =false;
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list<int>changeFromPrevLevel;
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list<int>levelGoesUp;
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list<int>levelGoDown;
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list<int>levelStaysSame;
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int totalChange=0;
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//we are going to walk the levels and see what the change is.
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//the frontIt is the front number (starts at 2nd entry)
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//backIt is the first entry (starts at 1st entry)
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auto frontIt = currentLevels.begin();
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frontIt++;
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auto backIt = currentLevels.begin();
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for(int index = 1;frontIt!=currentLevels.end();index++){
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int change = (*frontIt) - (*backIt);
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totalChange+=change;
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changeFromPrevLevel.push_back(change);
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frontIt++;
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backIt++;
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if (change>0){
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levelGoesUp.push_front(index);
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} else if(change<0){
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levelGoDown.push_front(index);
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} else {
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levelStaysSame.push_front(index);
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}
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}
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if (totalChange>0){
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dir= UP;
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} else if (totalChange<0){
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dir = DOWN;
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}
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if (dir==UP&&levelGoDown.size()>1){ //if the overall direction goes up and more then 1 level go down the list is bad
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currentLevels.clear();
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} else if (dir==DOWN&&levelGoesUp.size()>1){ //same as above but opiosite dirrection
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currentLevels.clear();
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}
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if (levelStaysSame.size()>1){ //cant have more then 1 number the same or the list is bad
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currentLevels.clear();
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}
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if (!currentLevels.empty()&&levelStaysSame.size()==1){
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auto itNumberToDelete = currentLevels.begin();
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advance(itNumberToDelete,levelStaysSame.front());
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currentLevels.erase(itNumberToDelete);
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listDirty = true;
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}
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if (!currentLevels.empty()){
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if (dir==UP&&levelGoDown.size()==1){
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list<int>::iterator itNumberToDelete = currentLevels.begin();
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advance(itNumberToDelete,levelGoDown.front());
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currentLevels.erase(itNumberToDelete);
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listDirty = true;
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} else if (dir==DOWN&&levelGoesUp.size()==1){
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auto itNumberToDelete = currentLevels.begin();
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advance(itNumberToDelete,levelGoesUp.front());
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currentLevels.erase(itNumberToDelete);
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listDirty=true;
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}
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int numOfLevelsInLine = currentLevels.size();
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//need to pull the first one to have something to compare to
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int prevlevel = currentLevels.front();
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currentLevels.pop_front();
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numOfLevelsProcessed++;
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for (int level = currentLevels.front(); !currentLevels.empty();level=currentLevels.front()){
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if (abs(prevlevel-level)>3) {currentLevels.clear();break;}
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prevlevel=currentLevels.front();
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currentLevels.pop_front();
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numOfLevelsProcessed++;
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if(numOfLevelsProcessed==numOfLevelsInLine){
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safeReports++;
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}
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}
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}
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}
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cout << safeReports;
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puzzle.close();
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} |