prettier

day6.c

@@ -1,7 +1,6 @@
 #include "lib.h"
 
 #define DBG 0
-#define PRETTY 1
 
 static
 ch input[] = {
@@ -13,42 +12,11 @@ ch test[] = {
 #embed "day6_test.txt"
 };
 
-#if PRETTY
-struct line {
-    union {
-        ch l[24];
-        struct {
-            ch vs[16];
-            ch pad[4];
-            num v;
-        };
-    };
-} __attribute__((aligned(0x40)));
-static_assert(alignof(struct line) == 0x40);
-#endif
-
-#if PRETTY
-alignas(0x40) static
-struct line linemem[6];
-struct line *const op_line = &linemem[1];
-struct line *const a_line = &linemem[2];
-struct line *const b_line = &linemem[3];
-struct line *const result_line = &linemem[4];
-#endif
-
 static
 num do_part1(size_t file_len, ch file[file_len]) {
     ch *s = file;
     num result = 0;
 
-#if PRETTY
-    memset(linemem, 0, sizeof(linemem));
-    snprintd(result, 16, result_line->vs);
-#endif
-#if DBG
-    print("\n");
-#endif
-
     s = memchr(s, '\n', file_len);
     num stride = s - file;
 
@@ -58,11 +26,6 @@ num do_part1(size_t file_len, ch file[file_len]) {
     num height  = (s - file) / stride;
     ch *op = s;
 
-#if DBG
-    print("STRIDE\t"); printd(stride); print("\n");
-    print("HEIGHT\t"); printd(height); print("\n");
-#endif
-
     // constructing a pointer more than 1 past the end of an array
     // is UB, sadly, so we'll use offsets
     num op_off = op - file;
@@ -72,74 +35,31 @@ num do_part1(size_t file_len, ch file[file_len]) {
         if (s[op_off] == '+') {
             num a = 0;
             num rem = height;
-#if PRETTY
-            op_line->vs[15] = '+';
-            a_line->v = a;
-            snprintd(a, 16, a_line->vs);
-            *b_line = (struct line){ };
-#endif
             do {
                 ch *t = s + ledge_off;
                 while (*t < '0') t++;
                 num b = grabnum(t, NULL);
-#if PRETTY
-                b_line->v = b;
-                snprintd(b, 16, b_line->vs);
-#endif
-#if DBG
-                if (rem < height) { print("\t+\t"); }
-                printd(b);
-#endif
                 a += b;
-#if PRETTY
-                a_line->v = a;
-                snprintd(a, 16, a_line->vs);
-#endif
                 ledge_off += stride;
                 rem--;
             } while (rem);
             result += a;
-#if PRETTY
-            result_line->v = result;
-            snprintd(result, 16, result_line->vs);
-#endif
-#if DBG
-            print("\t= "); printd(a); print("\n");
-#endif
         } else if (s[op_off] == '*') {
             num a = 1;
-#if PRETTY
-            op_line->vs[15] = '*';
-            a_line->v = a;
-            snprintd(a, 16, a_line->vs);
-            *b_line = (struct line){ };
-#endif
             num rem = height;
             do {
                 ch *t = s + ledge_off;
                 while (*t < '0') t++;
                 num b = grabnum(t, NULL);
-#if PRETTY
-                b_line->v = b;
-                snprintd(b, 16, b_line->vs);
-#endif
 #if DBG
                 if (rem < height) { print("\t*\t"); }
                 printd(b);
 #endif
                 a *= b;
-#if PRETTY
-                a_line->v = a;
-                snprintd(a, 16, a_line->vs);
-#endif
                 ledge_off += stride;
                 rem--;
             } while (rem);
             result += a;
-#if PRETTY
-            result_line->v = result;
-            snprintd(result, 16, result_line->vs);
-#endif
 #if DBG
             print("\t= "); printd(a); print("\n");
 #endif
@@ -158,12 +78,6 @@ num do_part1(size_t file_len, ch file[file_len]) {
         }
     } while (op_off < file_len);
 
-#if PRETTY
-    *op_line = (struct line){ };
-    *a_line = (struct line){ };
-    *b_line = (struct line){ };
-#endif
-
     return result;
 }
 
@@ -172,10 +86,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
     ch *s = file;
     num result = 0;
 
-#if PRETTY
-    memset(linemem, 0, sizeof(linemem));
-    snprintd(result, 16, result_line->vs);
-#endif
 #if DBG
     print("\n");
 #endif
@@ -212,12 +122,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
             num a = 0;
             num rem = redge_off - ledge_off + 1;
             num frem = rem;
-#if PRETTY
-            op_line->vs[15] = '+';
-            a_line->v = a;
-            snprintd(a, 16, a_line->vs);
-            *b_line = (struct line){ };
-#endif
             do {
                 num b = 0;
                 ch *t = s + redge_off;
@@ -227,10 +131,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
                         b += *t - '0';
                     }
                 }
-#if PRETTY
-                b_line->v = b;
-                snprintd(b, 16, b_line->vs);
-#endif
 #if DBG
                 if (rem < frem) { print("\t+\t"); }
                 printd(b);
@@ -240,10 +140,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
                 rem--;
             } while (rem);
             result += a;
-#if PRETTY
-            result_line->v = result;
-            snprintd(result, 16, result_line->vs);
-#endif
 #if DBG
             print("\t=\t"); printd(a); print("\n");
 #endif
@@ -251,12 +147,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
             num a = 1;
             num rem = redge_off - ledge_off + 1;
             num frem = rem;
-#if PRETTY
-            op_line->vs[15] = '*';
-            a_line->v = a;
-            snprintd(a, 16, a_line->vs);
-            *b_line = (struct line){ };
-#endif
             do {
                 num b = 0;
                 ch *t = s + redge_off;
@@ -266,10 +156,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
                         b += *t - '0';
                     }
                 }
-#if PRETTY
-                b_line->v = b;
-                snprintd(b, 16, b_line->vs);
-#endif
 #if DBG
                 if (rem < frem) { print("\t*\t"); }
                 printd(b);
@@ -279,10 +165,6 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
                 rem--;
             } while (rem);
             result += a;
-#if PRETTY
-            result_line->v = result;
-            snprintd(result, 16, result_line->vs);
-#endif
 #if DBG
             print("\t=\t"); printd(a); print("\n");
 #endif
@@ -296,17 +178,11 @@ num do_part2(size_t file_len, unsigned char file[file_len]) {
         prev_op_off = op_off;
     } while (prev_op_off != fop_off);
 
-#if PRETTY
-    *op_line = (struct line){ };
-    *a_line = (struct line){ };
-    *b_line = (struct line){ };
-#endif
-
     return result;
 }
 
-#define RUN_TEST1 0
+#define RUN_TEST1 1
-#define RUN_PART1 0
+#define RUN_PART1 1
 #define RUN_TEST2 1
 #define RUN_PART2 1
 

day6pretty.c

@@ -0,0 +1,228 @@
+#include "lib.h"
+
+static
+ch input[] = {
+#embed "day6_input.txt"
+};
+
+static
+ch test[] = {
+#embed "day6_test.txt"
+};
+
+typedef struct { ch l[64]; } line;
+static_assert(sizeof(line) == 0x40);
+
+alignas(0x40) static
+struct {
+    line padstart[4];
+    struct { num pad[3]; num prev_op_off, op_off, ledge_off, redge_off, rem; };
+    union { line l; struct { ch s[16]; num op, pad0, pad1, v; }; } b;
+    union { line l; struct { ch s[16], pad0, sr[16], pad1; num v, vr; }; } a;
+    line padend;
+} m;
+static_assert(offsetof(typeof(m),b) % 64 == 0);
+static_assert(sizeof(m.b) == 64);
+static_assert(sizeof(m.a) == 64);
+static_assert(offsetof(typeof(m),padend) % 64 == 0);
+
+static
+num do_part1(size_t file_len, ch file[file_len]) {
+    ch *s = file;
+    m = (typeof(m)){ };
+
+    s = memchr(s, '\n', file_len);
+    const num stride = s - file;
+
+    s = file;
+    while (*s != '+' && *s != '*') s += stride;
+    const num heightb = (s - file);
+    const num height  = (s - file) / stride;
+    ch *const op = s;
+
+    // constructing a pointer more than 1 past the end of an array
+    // is UB, sadly, so we'll use offsets
+    m.op_off = op - file;
+    s = file;
+    do {
+        m.ledge_off = m.op_off - heightb;
+        if (s[m.op_off] == '+') {
+            m.a.v = 0;
+            m.rem = height;
+            m.b.op = '+' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+            do {
+                ch *t = s + m.ledge_off;
+                while (*t < '0') t++;
+                m.b.v = grabnum(t, NULL);
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v += m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.ledge_off += stride;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        } else if (s[m.op_off] == '*') {
+            m.a.v = 1;
+            m.rem = height;
+            m.b.op = '*' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+            do {
+                ch *t = s + m.ledge_off;
+                while (*t < '0') t++;
+                m.b.v = grabnum(t, NULL);
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v *= m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.ledge_off += stride;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        }
+        m.op_off++;
+        while (m.op_off < file_len) {
+            if (s[m.op_off] == '+' || s[m.op_off] == '*')
+                break;
+            m.op_off++;
+        }
+    } while (m.op_off < file_len);
+
+    return m.a.vr;
+}
+
+static
+num do_part2(size_t file_len, unsigned char file[file_len]) {
+    ch *s = file;
+    m = (typeof(m)){ };
+
+    s = memchr(s, '\n', file_len);
+    const num stride = s - file;
+
+    s = file;
+    while (*s != '+' && *s != '*') s += stride;
+    const num heightb = (s - file);
+    const num height  = (s - file) / stride;
+    ch *const op = s;
+
+    // constructing a pointer more than 1 past the end of an array
+    // is UB, sadly, so we'll use offsets
+    const num fop_off = op - file;
+    m.prev_op_off = fop_off + stride - 1;
+    s = file;
+    do {
+        // we don't need to do these in the same order as the example
+        // because both these operations are commutative.
+        // but you know what? we can anyway. for fun. and pretty output
+        {
+            num op_off = m.prev_op_off - 1;
+            while (s[op_off] != '+' && s[op_off] != '*' && s[op_off] != '\n')
+                op_off--;
+            m.op_off = op_off;
+        }
+        m.ledge_off = m.op_off - heightb;
+        m.redge_off = (s[m.prev_op_off] == '\n' ? -1 : -2) + m.prev_op_off - heightb;
+        if (s[m.op_off] == '+') {
+            m.a.v = 0;
+            m.rem = m.redge_off - m.ledge_off + 1;
+            const num frem = m.rem;
+
+            m.b.op = '+' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+
+            do {
+                m.b.v = 0;
+                ch *t = s + m.redge_off;
+                for (num i = height; i; i--,t+=stride) {
+                    if (*t >= '0') {
+                        m.b.v *= 10;
+                        m.b.v += *t - '0';
+                    }
+                }
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v += m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.redge_off--;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        } else if (s[m.op_off] == '*') {
+            m.a.v = 1;
+            m.rem = m.redge_off - m.ledge_off + 1;
+            const num frem = m.rem;
+
+            m.b.op = '*' << 8;
+            snprintd(m.a.v, 16, m.a.s);
+
+            do {
+                m.b.v = 0;
+                ch *t = s + m.redge_off;
+                for (num i = height; i; i--,t+=stride) {
+                    if (*t >= '0') {
+                        m.b.v *= 10;
+                        m.b.v += *t - '0';
+                    }
+                }
+                snprintd(m.b.v, 16, m.b.s);
+                m.a.v *= m.b.v;
+                snprintd(m.a.v, 16, m.a.s);
+                m.redge_off--;
+                m.rem--;
+            } while (m.rem);
+            m.a.vr += m.a.v;
+            snprintd(m.a.vr, 16, m.a.sr);
+        }
+
+        m.prev_op_off = m.op_off;
+    } while (m.prev_op_off != fop_off);
+
+    return m.a.vr;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 4277556
+#define TEST2_EXPECT 3263827
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test); v != TEST1_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST1_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART1
+    print("PART 1 RESULT: ");
+    printd(do_part1(countof(input), input));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test); v != TEST2_EXPECT) {
+        print("FAILED (got ");
+        printd(v);
+        print(", expected " xstr(TEST2_EXPECT) ")\n");
+    } else {
+        print("PASSED\n");
+    }
+#endif
+
+#if RUN_PART2
+    print("PART 2 RESULT: ");
+    printd(do_part2(countof(input), input));
+    print("\n");
+#endif
+
+    exit_group(0);
+}