1 files changed, 106 insertions, 0 deletions
diff --git a/advent-of-code/2022/08/1.c b/advent-of-code/2022/08/1.c
new file mode 100644
index 0000000..6f69c97
--- /dev/null
+++ b/advent-of-code/2022/08/1.c
@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct {
+    uint8_t *data;
+    int rows;
+    int columns;
+    int cap;
+} Mat;
+
+int get(Mat *m, int row, int column) {
+    return m->data[row * m->columns + column];
+}
+
+void set(Mat *m, int row, int column, uint8_t value) {
+    m->data[row * m->columns + column] = value;
+}
+
+char buf[4096];
+
+int main() {
+    Mat m;
+    m.data = malloc(4096);
+    m.cap = 4096;
+    m.rows = 0;
+    m.columns = 0;
+    
+    
+    FILE *fp = fopen("input", "r");
+    while(fgets(buf, 4096, fp)) {
+        int len = strlen(buf);
+        if (len <= 1) break;
+        if (m.columns == 0) m.columns = len - 1;
+        while (m.cap < (m.rows + 1) * m.columns) {
+            m.data = realloc(m.data, m.cap * 2);
+            m.cap *= 2;
+        }
+        memcpy(m.data + m.rows * m.columns, buf, m.columns);
+        m.rows++;
+    }
+    
+    Mat vis = m;
+    vis.data = malloc(m.rows * m.columns);
+    vis.cap = m.rows * m.columns;
+    memset(vis.data, 0, vis.cap);
+    
+    // top-down scan
+    for (int i = 0; i < m.columns; i++) {
+        int curmax = -1;
+        for (int j = 0; j < m.rows; j++) {
+            if (get(&m, j, i) > curmax) {
+                set(&vis, j, i, 1);
+                curmax = get(&m, j, i);
+            }
+        }
+    }
+    // down-top scan
+    for (int i = 0; i < m.columns; i++) {
+        int curmax = -1;
+        for (int j = m.rows - 1; j >= 0; j--) {
+            if (get(&m, j, i) > curmax) {
+                set(&vis, j, i, 1);
+                curmax = get(&m, j, i);
+            }
+        }
+    }
+    
+    // left-right scan
+    for (int i = 0; i < m.rows; i++) {
+        int curmax = -1;
+        for (int j = 0; j < m.columns; j++) {
+            if (get(&m, i, j) > curmax) {
+                set(&vis, i, j, 1);
+                curmax = get(&m, i, j);
+            }
+        }
+    }
+    
+    // right-left scan
+    for (int i = 0; i < m.rows; i++) {
+        int curmax = -1;
+        for (int j = m.columns - 1; j >= 0; j--) {
+            if (get(&m, i, j) > curmax) {
+                set(&vis, i, j, 1);
+                curmax = get(&m, i, j);
+            }
+        }
+    }
+    
+    // count
+    int count = 0;
+    for (int i = 0; i < m.columns; i++) {
+        int curmax = -1;
+        for (int j = 0; j < m.rows; j++) {
+            if (get(&vis, j, i) > 0) {
+                count++;
+            }
+        }
+    }
+    
+    printf("%d", count);
+    return 0;
+}
+