From 181bed144cee30ca570a3f3128d92c888efb3bb8 Mon Sep 17 00:00:00 2001
From: Mistivia <i@mistivia.com>
Date: Tue, 23 Dec 2025 22:10:21 +0800
Subject: day 10 part 1

---
 10/Makefile |  13 +++++
 10/part1.c  | 184 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 197 insertions(+)
 create mode 100644 10/Makefile
 create mode 100644 10/part1.c

diff --git a/10/Makefile b/10/Makefile
new file mode 100644
index 0000000..7d325ba
--- /dev/null
+++ b/10/Makefile
@@ -0,0 +1,13 @@
+all: part1 part2
+
+part1: part1.c
+	gcc -Wall -g part1.c -o part1 -lalgds
+
+part2: part2.c
+	gcc -Wall -g part2.c -o part2 -lalgds
+
+1: part1
+	cat input | ./part1
+
+2: part2
+	cat input | ./part2
\ No newline at end of file
diff --git a/10/part1.c b/10/part1.c
new file mode 100644
index 0000000..5348830
--- /dev/null
+++ b/10/part1.c
@@ -0,0 +1,184 @@
+#include <algds/sort.h>
+#include <algds/type_alias.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include <algds/vec.h>
+#include <algds/str.h>
+#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#define PANIC do { \
+    fprintf(stderr, "panic at %s:%d\n", __FILE__, __LINE__); \
+    abort(); \
+} while (0)
+
+void expect_char(char e) {
+    int c = fpeek(stdin);
+    if (c != e) {
+        PANIC;
+    }
+    fgetc(stdin);
+}
+
+bool string2long(const char *s, long *num) {
+    char *end;
+    errno = 0;
+    *num = strtol(s, &end, 10);
+    if (end == s) {
+        return false;
+    }
+    if (errno != 0) {
+        return false;
+    }
+    return true;
+}
+
+int64_t parse_integer() {
+    long ret;
+    StrBuilder sb;
+    StrBuilder_init(&sb);
+    while (1) {
+        int c = fpeek(stdin);
+        if (isdigit(c)) {
+            fgetc(stdin);
+            StrBuilder_append_char(&sb, c);
+        } else {
+            break;
+        }
+    }
+    if (strlen(sb.buf) == 0) {
+        PANIC;
+    }
+    StrBuilder_append_char(&sb, '\0');
+    if (!string2long(sb.buf, &ret)) {
+        PANIC;
+    }
+    free(sb.buf);
+    return ret;
+}
+
+uint32_t parse_indicator() {
+    expect_char('[');
+    uint32_t ret = 0;
+    int n = 0;
+    while (1) {
+        int c = fpeek(stdin);
+        if (c == '.') {
+            getchar();
+        } else if (c == '#') {
+            getchar();
+            // printf("n=%d\n", n);
+            ret |= (1 << n);
+            // printf("ret=%d\n", ret);
+        } else {
+            break;
+        }
+        n++;
+    }
+    expect_char(']');
+    return ret;
+}
+
+uint32_t parse_button() {
+    uint32_t ret = 0;
+    expect_char('(');
+    while (1) {
+        long num = parse_integer();
+        ret |= (1 << num);
+        int c = fpeek(stdin);
+        if (c == ',') {
+            getchar();
+        } else {
+            break;
+        }
+    }
+    expect_char(')');
+    return ret;
+}
+
+void skip_space() {
+    while (1) {
+        int c = fpeek(stdin);
+        if (c == EOF) return;
+        if (isspace(c)) {
+            fgetc(stdin);
+        } else {
+            return;
+        }
+    }
+}
+
+UIntVector parse_buttons() {
+    skip_space();
+    UIntVector ret;
+    UIntVector_init(&ret);
+    while (1) {
+        int c = fpeek(stdin);
+        if (c == '(') {
+            uint32_t btn = parse_button();
+            UIntVector_push_back(&ret, btn);
+            skip_space();
+        } else {
+            break;
+        }
+    }
+    return ret;
+}
+
+void skip_to_line_end() {
+    while (1) {
+        int c = getchar();
+        if (c != '\n' && c != EOF) {
+            continue;
+        } else {
+            break;
+        }
+    }
+}
+
+void solve_impl(uint32_t target, UIntVector *buttons, uint32_t curind, int curbtn, int curtimes, int *mintimes) {
+    if (target == curind) {
+        if (curtimes < *mintimes) {
+            *mintimes = curtimes;
+        }
+    }
+    if (curbtn >= buttons->size) {
+        return;
+    }
+    uint32_t btn = buttons->buffer[curbtn];
+    solve_impl(target, buttons, curind, curbtn+1, curtimes, mintimes);
+    solve_impl(target, buttons, curind ^ btn, curbtn+1, curtimes+1, mintimes);
+}
+
+int solve(uint32_t indicator, UIntVector *buttons) {
+    int mintimes = INT_MAX;
+    solve_impl(indicator, buttons, 0, 0, 0, &mintimes);
+    if (mintimes == INT_MAX) {
+        PANIC;
+    }
+    return mintimes;
+}
+
+int main() {
+    int r = 0;
+    while (1) {
+        int c = fpeek(stdin);
+        if (c == '[') {
+            uint32_t indicator = parse_indicator();
+            UIntVector buttons = parse_buttons();
+            // printf("%d\n", indicator);
+            // UIntVector_show(buttons, stdout); puts("");
+            fflush(stdout);
+            int solution = solve(indicator, &buttons);
+            r += solution;
+            // printf("solution=%d\n", solution);
+            skip_to_line_end();
+        } else {
+            break;
+        }
+    }
+    printf("%d\n", r);
+    return 0;
+}
\ No newline at end of file
-- 
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