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import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class day03 {
public static void main(String args[]) throws IOException {
RandomAccessFile input = new RandomAccessFile("input", "r");
System.out.println("Day 01 Part 1: " + part1(input));
input.seek(0);
System.out.println("Day 01 Part 2: " + part2(input));
input.close();
}
public static String part1(RandomAccessFile input) throws IOException {
String line;
int row = 0;
ArrayList<Number> numbers = new ArrayList<>();
ArrayList<Symbol> symbols = new ArrayList<>();
while ((line = input.readLine()) != null) {
getNumbers(numbers, row, line);
getSymbols(symbols, row, line);
row += 1;
}
int tot = 0;
for (Number num: numbers) {
boolean part = false;
for (Symbol sym: symbols) {
for (int col = num.colstart - 1; col <= num.colend + 1; col++) {
if (sym.row == num.row - 1 && sym.col == col) {
part = true;
}
if (sym.row == num.row + 1 && sym.col == col) {
part = true;
}
}
if (sym.row == num.row && sym.col == num.colstart - 1) {
part = true;
}
if (sym.row == num.row && sym.col == num.colend + 1) {
part = true;
}
}
if (part) {
tot += num.value;
}
}
return Integer.toString(tot);
}
public static String part2(RandomAccessFile input) throws IOException {
String line;
int row = 0;
ArrayList<Number> numbers = new ArrayList<>();
ArrayList<Symbol> symbols = new ArrayList<>();
while ((line = input.readLine()) != null) {
getNumbers(numbers, row, line);
getSymbols(symbols, row, line);
row += 1;
}
int tot = 0;
for (Symbol sym : symbols) {
if (!sym.symbol.equals("*")) {
continue;
}
ArrayList<Number> neighs = new ArrayList<>();
for (Number num: numbers) {
if (num.contains(sym.row - 1, sym.col - 1) ||
num.contains(sym.row - 1, sym.col ) ||
num.contains(sym.row - 1, sym.col + 1) ||
num.contains(sym.row , sym.col - 1) ||
num.contains(sym.row , sym.col + 1) ||
num.contains(sym.row + 1, sym.col - 1) ||
num.contains(sym.row + 1, sym.col ) ||
num.contains(sym.row + 1, sym.col + 1)) {
if (!neighs.contains(num)) {
neighs.add(num);
}
}
}
if (!(neighs.size() == 2)) {
continue;
}
int ratio = neighs.get(0).value * neighs.get(1).value;
tot += ratio;
}
return Integer.toString(tot);
}
private static void getNumbers(ArrayList<Number> numbers, int row, String line) {
Pattern pat = Pattern.compile("\\d+");
Matcher mat = pat.matcher(line);
while (mat.find()) {
numbers.add(
new Number(
row,
mat.start(),
mat.end() - 1,
Integer.parseInt(mat.group())
)
);
}
}
private static void getSymbols(ArrayList<Symbol> symbols, int row, String line) {
Pattern pat = Pattern.compile("[^0-9.]");
Matcher mat = pat.matcher(line);
while (mat.find()) {
symbols.add(
new Symbol(
row,
mat.start(),
mat.group()
)
);
}
}
}
class Number {
int row, colstart, colend, value;
public Number(int row, int colstart, int colend, int value) {
this.row = row;
this.colstart = colstart;
this.colend = colend;
this.value = value;
}
public boolean contains(int row, int col) {
return (row == this.row) && (this.colstart <= col && col <= this.colend);
}
public String toString() {
return "[" + this.row + ", " + this.colstart + "-" + this.colend + "]: " + this.value;
}
}
class Symbol {
int row, col;
String symbol;
public Symbol(int row, int col, String symbol) {
this.row = row;
this.col = col;
this.symbol = symbol;
}
public String toString() {
return "[" + this.row + ", " + this.col + "]: " + this.symbol;
}
}
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