1 files changed, 58 insertions, 0 deletions

diff --git a/2023/07/7a.c b/2023/07/7a.c
new file mode 100644
index 0000000..ffc9b5c
--- /dev/null
+++ b/2023/07/7a.c
@@ -0,0 +1,58 @@
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define N 100000
+
+int value[255] = {
+        ['2'] = 2, ['3'] = 3, ['4'] = 4, ['5'] = 5,
+        ['6'] = 6, ['7'] = 7, ['8'] = 8, ['9'] = 9,
+        ['T'] = 10, ['J'] = 11, ['Q'] = 12, ['K'] = 13, ['A'] = 14
+};
+
+typedef struct {
+        char c[5];
+        int64_t b;
+} hand_t;
+
+int strength(hand_t h) {
+        int i, c2, c1, s, x[15];
+
+        memset(x, 0, 15 * sizeof(int));
+        for (i = 0, s = 0; i < 5; i++) {
+                s = s * 15 + value[h.c[i]];
+                x[value[h.c[i]]]++;
+        }
+        for (i = 2, c1 = 0, c2 = 0; i < 15; i++) {
+                if (c1 < x[i]) {
+                        c2 = c1;
+                        c1 = x[i];
+                } else if (c2 < x[i]) c2 = x[i];
+        }
+
+        return (c1*5 + c2) * 759375 + s;
+}
+
+int compare(const void *h1, const void *h2) {
+        return strength(*(hand_t *)h1) - strength(*(hand_t *)h2);
+}
+
+int main() {
+        char line[N];
+        hand_t hand[N];
+        int64_t i, n, p;
+
+        for (n = 0; fgets(line, N, stdin) != NULL; n++) {
+                memcpy(hand[n].c, line, 5);
+                hand[n].b = atoll(line+6);
+        }
+
+        qsort(hand, n, sizeof(hand_t), &compare);
+
+        for (i = 0, p = 0; i < n; i++)
+                p += hand[i].b * (i+1);
+
+        printf("%" PRId64 "\n", p);
+        return 0;
+}