Files
advent-of-code-2024/app.cpp
Daniel Ledda 81bf17ae81 update
2024-12-27 13:12:42 +01:00

284 lines
8.0 KiB
C++

#include <math.h>
#include "core.hpp"
int day1() {
Arena arena = createArena(Megabytes(16));
list<char> file = readEntireFile(&arena, strlit("./day-1-input"));
int LIST_SIZE = 1000;
int *firsts = PushArray(&arena, int, LIST_SIZE);
int *seconds = PushArray(&arena, int, LIST_SIZE);
char currentNum[5];
int numIndex = 0;
int line = 0;
int *target = firsts;
for (int i = 0; i < file.length; i++) {
char c = file.data[i];
if (c == ' ') {
continue;
} else if (c == '\n') {
line++;
continue;
} else {
currentNum[numIndex++] = c;
}
if (numIndex == 5) {
target[line] = atoi(currentNum);
if (target == firsts) {
target = seconds;
} else {
target = firsts;
}
numIndex = 0;
}
}
qsort(firsts, line, sizeof(int), cmpint);
qsort(seconds, line, sizeof(int), cmpint);
int sum = 0;
for (int i = 0; i < line; i++) {
int dist = firsts[i] - seconds[i];
if (dist < 0) {
dist *= -1;
}
sum += dist;
}
printf("%i\n", sum);
// Part 2
int total = 0;
for (int i = 0; i < line; i++) {
int firstElement = firsts[i];
int countInSecondList = 0;
for (int j = 0; j < line; j++) {
if (seconds[j] == firstElement) {
countInSecondList++;
}
}
total += firstElement * countInSecondList;
}
printf("%i\n", total);
return 0;
}
int day2_main() {
Arena arena = createArena(Megabytes(16));
list<char> file = readEntireFile(&arena, strlit("./day-2-input"));
int safes = 0;
int lines = 0;
int fileReadIndex = 0;
list<int> nums = PushList(&arena, int, 100);
list<char> numStr = PushList(&arena, char, 16);
list<int> modifiedNums = PushList(&arena, int, nums.capacity);
while (fileReadIndex < file.length) {
int linestart = fileReadIndex;
int lineend = fileReadIndex;
while (file.data[lineend] != '\n' && lineend < file.length) {
lineend++;
}
lines++;
zeroList(&nums);
for (int j = linestart; j < lineend; j++) {
if (file.data[j] != ' ') {
appendList(&numStr, (char)file.data[j]);
}
if (file.data[j] == ' ' || j == lineend - 1) {
appendList(&numStr, '\0');
appendList(&nums, atoi(numStr.data));
zeroList(&numStr);
}
}
int unsafes = 0;
for (int i = 0; i < nums.length + 1; i++) {
int skipIndex = i - 1;
zeroList(&modifiedNums);
for (int modifiedIndex = 0; modifiedIndex < nums.length; modifiedIndex++) {
if (modifiedIndex == skipIndex) {
continue;
}
appendList(&modifiedNums, nums.data[modifiedIndex]);
}
bool increasing = modifiedNums.data[0] < modifiedNums.data[1];
bool safe = true;
for (int checkIndex = 0; checkIndex < modifiedNums.length - 1; checkIndex++) {
int next = checkIndex + 1;
int diff = increasing ? modifiedNums.data[next] - modifiedNums.data[checkIndex] : modifiedNums.data[checkIndex] - modifiedNums.data[next];
if (diff < 1 || diff > 3) {
safe = false;
break;
}
}
if (!safe) {
unsafes += 1;
} else {
break;
}
}
if (unsafes <= nums.length) {
safes++;
}
fileReadIndex = lineend + 1;
}
printf("safes: %i", safes);
printf("\n");
printf("lines: %i", lines);
printf("\n");
printf("Arena: %zu, %zu", arena.head, arena.capacity);
printf("\n");
return 0;
}
bool stringContains(string str, char c) {
for (size_t i = 0; i < str.len; i++) {
if (str.str[i] == c) {
return true;
}
}
return false;
}
const char NUMERIC_CHARS[] = "1234567890";
inline bool isNumeric(char c) {
return stringContains(strlit(NUMERIC_CHARS), c);
}
inline int parsePositiveInt(string str, size_t *lengthPointer) {
size_t numEnd = 0;
char currChar = str.str[numEnd];
while (numEnd < str.len && isNumeric(currChar)) {
currChar = str.str[++numEnd];
*lengthPointer += 1;
}
*lengthPointer -= 1;
if (numEnd > 0) {
int result = 0;
for (int i = 0; i < numEnd; i++) {
result *= 10;
result += (double)(str.str[i] - '0');
}
return result;
} else {
return -1;
}
}
int day3_main() {
Arena arena = createArena(Megabytes(16));
list<char> file = readEntireFile(&arena, strlit("./day-3-input"));
string mulBegin = strlit("mul(");
string doIdent = strlit("do()");
string dontIdent = strlit("don't()");
int result = 0;
size_t c = 0;
bool skip = false;
while (c < file.length) {
if (!skip) {
if (file.data[c] == 'm') {
string segment = strSlice(file.data, c, c+mulBegin.len);
int first = -1;
int second = -1;
if (strEql(segment, mulBegin)) {
c += segment.len;
first = parsePositiveInt(strSlice(file.data, c, file.length - c), &c);
if (file.data[c + 1] == ',') {
c += 2;
second = parsePositiveInt(strSlice(file.data, c, file.length - c), &c);
if (second != -1 && file.data[c + 1] == ')') {
c += 1;
result += first * second;
}
}
}
} else if (file.data[c] == 'd') {
string segment = strSlice(file.data, c, c+dontIdent.len);
if (strEql(segment, dontIdent)) {
skip = true;
c += dontIdent.len - 1;
}
}
} else {
if (file.data[c] == 'd') {
string segment = strSlice(file.data, c, c+doIdent.len);
if (strEql(segment, doIdent)) {
skip = false;
c += doIdent.len - 1;
}
}
}
c++;
}
printf("total: %i\n", result);
return 0;
}
int day4_main() {
Arena mainArena = createArena(Megabytes(16));
Arena *arena = &mainArena;
list<char> file = readEntireFile(arena, strlit("./day-4-input"));
int fileReadIndex = 0;
int lines = 0;
int lineLength = 0;
while (fileReadIndex < file.length) {
int linestart = fileReadIndex;
int lineend = fileReadIndex;
while (file.data[lineend] != '\n' && lineend < file.length) {
lineend++;
}
if (lineLength == 0) {
lineLength = lineend - linestart;
} else if (lineend - linestart != lineLength) {
fputs("Bad input. One or more lines aren't the same length as the first line.", stderr);
return 1;
}
lines++;
fileReadIndex += lineLength + 1;
}
string xmas = strlit("XMAS");
int count = 0;
for (int c = 0; c < file.length; c++) {
string strings[] = {
//forwards
strSlice(file.data, c, c+xmas.len),
//down
strSlice(file.data, c, c+xmas.len),
//forwardsReverse
strReverse(arena, strSlice(file.data, c, c+xmas.len)),
//downReverse
strReverse(arena, strSlice(file.data, c, c+xmas.len)),
};
for (size_t i = 0; i < ArrayCount(strings); i++) {
if (strEql(strings[i], xmas)) {
c += xmas.len;
count++;
}
}
}
printf("count: %i\n", count);
return 0;
}
int main() {
return day4_main();
}