day 7

Signed-off-by: Jack Bond-Preston <jackbondpreston@outlook.com>

7/7a.cpp

@@ -0,0 +1,38 @@
+#include <fstream>
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <climits>
+
+int main() {
+    std::ifstream infile("input.txt");
+
+    std::vector<int> positions {};
+
+    int curr = 0;
+    char comma;
+    while (infile >> curr) {
+        positions.push_back(curr);
+        infile >> comma;
+    }
+
+    int lowest = *std::min_element(std::begin(positions), std::end(positions));
+    int highest = *std::max_element(std::begin(positions), std::end(positions));
+
+    int lowest_cost = INT_MAX;
+    int best_position = 0;
+
+    for (int i = lowest; i < highest; i++) {
+        int fuel_cost = 0;
+        for (const auto &p : positions) {
+            fuel_cost += std::abs(p - i);
+        }
+
+        if (fuel_cost < lowest_cost) {
+            lowest_cost = fuel_cost;
+            best_position = i;
+        }
+    }
+
+    std::cout << lowest_cost << std::endl;
+}

7/7b.cpp

@@ -0,0 +1,41 @@
+#include <fstream>
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <climits>
+
+int main() {
+    std::ifstream infile("input.txt");
+
+    std::vector<int> positions {};
+
+    int curr = 0;
+    char comma;
+    while (infile >> curr) {
+        positions.push_back(curr);
+        infile >> comma;
+    }
+
+    int lowest = *std::min_element(std::begin(positions), std::end(positions));
+    int highest = *std::max_element(std::begin(positions), std::end(positions));
+
+    int lowest_cost = INT_MAX;
+    int best_position = 0;
+
+    for (int i = lowest; i < highest; i++) {
+        int fuel_cost = 0;
+        for (const auto &p : positions) {
+            int next_cost = 1;
+            for (int j = 0; j < std::abs(p - i); j++, next_cost++) {
+                fuel_cost += next_cost;
+            }
+        }
+
+        if (fuel_cost < lowest_cost) {
+            lowest_cost = fuel_cost;
+            best_position = i;
+        }
+    }
+
+    std::cout << lowest_cost << std::endl;
+}