day 8

day0.h

@@ -12,27 +12,36 @@ ch test[] = {
 #embed "day0_test.txt"
 };
 
+alignas(0x40) static
+struct {
+    line padstart[4];
+    struct { ch *s; num _extra[7]; };
+    union { line l; struct { ch s[16]; num n; }; } result;
+    line padend;
+} m;
+static_assert(offsetof(typeof(m),result) % 64 == 0);
+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)){ };
-    num result = 0;
+    m.s = file;
+    m.result.n = 0;
 
 #if DBG
     print("\n");
 #endif
 
 do {
-    s++;
+    m.s++;
-} while (s != &file[file_len]);
+} while (m.s != &file[file_len]);
 
-    return result;
+    return m.result.n;
 }
 
 static
 num do_part2(size_t file_len, ch file[file_len]) {
-    num result = 0;
+    return 0;
-    return result;
 }
 
 #define RUN_TEST1 1

day7.c

@@ -0,0 +1,178 @@
+#include "lib.h"
+
+#define DBG 0
+
+static
+ch input[32768] = {
+#embed "day7_input.txt"
+};
+
+static
+ch test[512] = {
+#embed "day7_test.txt"
+};
+
+typedef struct { ch l[64]; } line;
+static_assert(sizeof(line) == 0x40);
+
+alignas(0x40) static
+struct {
+    line padstart[4];
+    num file_stride;
+    num stride;
+    num _extra[6];
+    union { line l; struct { ch s[16]; num n; }; } result;
+    line padend;
+} m;
+static_assert(offsetof(typeof(m),result) % 64 == 0);
+static_assert(offsetof(typeof(m),padend) % 64 == 0);
+
+alignas(4096) ch buf1[256];
+alignas(4096) num buf[256];
+
+static
+num do_part1(size_t file_len, ch file[file_len]) {
+    m = (typeof(m)){ };
+    m.result.n = 0;
+#if DBG
+        pnl();
+#endif
+
+    memset(buf1, 0, sizeof(buf1));
+
+    m.file_stride = findc(file, '\n', file_len) - file;
+    num linecnt = (findc(file, 0, file_len) - file) / m.file_stride;
+#if DBG
+    print("stride "); printd(m.file_stride); pnl();
+    print("lines  "); printd(linecnt); pnl();
+#endif
+
+    num s_pos = findc(file, 'S', - 1) - 1 - file;
+    buf1[s_pos] = '|';
+    num line = 2;
+    do {
+        ch *l = file + line * m.file_stride;
+        for (num col = 0; col < m.file_stride - 1; col++) {
+            ch c = l[col];
+            if (c == '^') {
+                m.result.n += buf1[col] > 0;
+                buf1[col-1] |= buf1[col];
+                buf1[col+1] |= buf1[col];
+                buf1[col] = 0;
+            }
+        }
+#if DBG
+        for (num col = 0; col < m.file_stride; col++) {
+            if (buf1[col] == '|') print("|");
+            else if (l[col] == '^') print("^");
+            else print(" ");
+        }
+        pnl();
+#endif
+        line+=2;
+    } while (line < linecnt);
+
+    return m.result.n;
+}
+
+static
+num do_part2(size_t file_len, ch file[file_len]) {
+    m = (typeof(m)){ };
+#if DBG
+        pnl();
+#endif
+
+    memset(buf, 0, sizeof(buf));
+
+    m.file_stride = findc(file, '\n', file_len) - file;
+    num linecnt = (findc(file, 0, file_len) - file) / m.file_stride;
+#if DBG
+    print("stride "); printd(m.file_stride); pnl();
+    print("lines  "); printd(linecnt); pnl();
+#endif
+
+    num s_pos = findc(file, 'S', - 1) - 1 - file;
+    buf[s_pos] = 1;
+    num line = 2;
+    do {
+        ch *l = file + line * m.file_stride;
+        for (num col = 0; col < m.file_stride - 1; col++) {
+            ch c = l[col];
+            if (c == '^') {
+                buf[col-1] += buf[col];
+                buf[col+1] += buf[col];
+                buf[col] = 0;
+            }
+        }
+        for (num col = 0; col < m.file_stride; col++) {
+            num v = buf[col];
+#if DBG
+            if (l[col] == '^') print(" ");
+            else if (v >> 32) print("█");
+            else if (v >> 16) print("▓");
+            else if (v >>  8) print("▒");
+            else if (v >>  4) print("░");
+            else if (v >>  2) print("-");
+            else if (v >>  0) print(".");
+            else print(" ");
+#endif
+        }
+#if DBG
+        pnl();
+#endif
+        line+=2;
+    } while (line < linecnt);
+
+    m.result.n = 0;
+    for (num col = 0; col < m.file_stride; col++) {
+        m.result.n += buf[col];
+    }
+
+    return m.result.n;
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 21
+#define TEST2_EXPECT 40
+
+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);
+}

day8.c

@@ -0,0 +1,317 @@
+#include "lib.h"
+#include <stdlib.h>
+
+#define DBG 0
+
+static
+ch input[] = {
+#embed "day8_input.txt"
+};
+
+static
+ch test[] = {
+#embed "day8_test.txt"
+};
+
+
+typedef num point __attribute__((vector_size(4*sizeof(num))));
+
+alignas(64) static
+point positions[1000];
+
+alignas(64) static
+unsigned short circuits[1000];
+
+alignas(1024) static
+struct { num min_dist; unsigned short min_target; } targets[1000][1024];
+
+alignas(64) static
+unsigned short next_targets[1000];
+
+alignas(64) static
+num next_dists[1000];
+
+alignas(64) static
+unsigned short next_indices[1000];
+
+static
+int targetcompar(const void *a, const void *b) {
+    const num ad = ((typeof(**targets)*)a)->min_dist;
+    const num bd = ((typeof(**targets)*)b)->min_dist;
+    if (ad > bd) return 1;
+    else if (ad < bd) return -1;
+    else return 0;
+}
+
+static
+num do_part1(size_t file_len, ch file[file_len], bool istest) {
+    const num iters = istest ? 10 : 1000;
+    const num pointcount = istest ? 20 : 1000;
+    num iter = 0;
+#if DBG
+    pnl();
+#endif
+
+    // read in positions from file
+    { ch *s = file;
+    for (num i = 0; i < pointcount; i++) {
+        unsigned x = grabnum(s, &s);
+        s++;
+        unsigned y = grabnum(s, &s);
+        s++;
+        unsigned z = grabnum(s, &s);
+        s++;
+        positions[i] = (point){ x,y,z };
+    } }
+    // set up initial circuits
+    for (num i = 0; i < pointcount; i += 4) {
+        circuits[i+0] = i+0;
+        circuits[i+1] = i+1;
+        circuits[i+2] = i+2;
+        circuits[i+3] = i+3;
+    }
+    // find distances between all points
+    for (num i = 0; i < pointcount; i++) {
+        point pi = positions[i];
+        for (num j = 0; j < pointcount; j += 4) {
+            point pj0 = positions[j+0];
+            point pj1 = positions[j+1];
+            point pj2 = positions[j+2];
+            point pj3 = positions[j+3];
+
+            point dvp0 = (pi - pj0) * (pi - pj0);
+            point dvp1 = (pi - pj1) * (pi - pj1);
+            point dvp2 = (pi - pj2) * (pi - pj2);
+            point dvp3 = (pi - pj3) * (pi - pj3);
+
+            num d0 = dvp0[0] + dvp0[1] + dvp0[2] + dvp0[3];
+            num d1 = dvp1[0] + dvp1[1] + dvp1[2] + dvp1[3];
+            num d2 = dvp2[0] + dvp2[1] + dvp2[2] + dvp2[3];
+            num d3 = dvp3[0] + dvp3[1] + dvp3[2] + dvp3[3];
+
+            targets[i][j+0] = (typeof(**targets)) { d0, j+0 };
+            targets[i][j+1] = (typeof(**targets)) { d1, j+1 };
+            targets[i][j+2] = (typeof(**targets)) { d2, j+2 };
+            targets[i][j+3] = (typeof(**targets)) { d3, j+3 };
+        }
+        // sort targets. slow.
+        qsort(targets[i], pointcount, sizeof(**targets), targetcompar);
+    }
+    // set up initial next targets
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[i] = targets[i][1].min_target;
+        next_dists[i]   = targets[i][1].min_dist;
+        next_indices[i] = 1;
+    }
+
+    // FIXED JOIN ITERATIONS
+    do {
+        // find min dist
+        num min_dist = -1;
+        num min_i = 0;
+        for (num i = 0; i < pointcount; i++)
+            if (next_dists[i] < min_dist)
+                min_dist = next_dists[min_i = i];
+        num min_j = next_targets[min_i];
+        // -- join the pair --
+#if DBG
+        point ipos = positions[min_i];
+        point jpos = positions[min_j];
+        printd(ipos[0]); print(","); printd(ipos[1]); print(","); printd(ipos[2]);
+        print("\t->\t");
+        printd(jpos[0]); print(","); printd(jpos[1]); print(","); printd(jpos[2]);
+        pnl();
+#endif
+        // update circuits
+        unsigned old_circuit = circuits[min_j];
+        unsigned new_circuit = circuits[min_i];
+        if (old_circuit != new_circuit) {
+            for (num c = 0; c < pointcount; c++)
+                if (circuits[c] == old_circuit)
+                    circuits[c] = new_circuit;
+        }
+        // update targets
+        unsigned niidx = ++next_indices[min_i];
+        unsigned njidx = ++next_indices[min_j];
+        next_targets[min_i] = targets[min_i][niidx].min_target;
+        next_targets[min_j] = targets[min_j][njidx].min_target;
+        next_dists[min_i] = targets[min_i][niidx].min_dist;
+        next_dists[min_j] = targets[min_j][njidx].min_dist;
+
+        iter++;
+    } while(iter < iters);
+
+    // reuse next_targets to store circuit counts
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[i] = 0;
+    }
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[circuits[i]]++;
+    }
+    num circ0 = 0, circ1 = 0, circ2 = 0;
+    for (num i = 0; i < pointcount; i++) {
+        if (next_targets[i] > circ0) {
+            circ2 = circ1;
+            circ1 = circ0;
+            circ0 = next_targets[i];
+        } else if (next_targets[i] > circ1) {
+            circ2 = circ1;
+            circ1 = next_targets[i];
+        } else if (next_targets[i] > circ2) {
+            circ2 = next_targets[i];
+        }
+    }
+
+    return circ0 * circ1 * circ2;
+}
+
+static
+num do_part2(size_t file_len, ch file[file_len], bool istest) {
+    const num pointcount = istest ? 20 : 1000;
+#if DBG
+    pnl();
+#endif
+
+    // read in positions from file
+    { ch *s = file;
+    for (num i = 0; i < pointcount; i++) {
+        unsigned x = grabnum(s, &s);
+        s++;
+        unsigned y = grabnum(s, &s);
+        s++;
+        unsigned z = grabnum(s, &s);
+        s++;
+        positions[i] = (point){ x,y,z };
+    } }
+    // set up initial circuits
+    for (num i = 0; i < pointcount; i += 4) {
+        circuits[i+0] = i+0;
+        circuits[i+1] = i+1;
+        circuits[i+2] = i+2;
+        circuits[i+3] = i+3;
+    }
+    // find distances between all points
+    for (num i = 0; i < pointcount; i++) {
+        point pi = positions[i];
+        for (num j = 0; j < pointcount; j += 4) {
+            point pj0 = positions[j+0];
+            point pj1 = positions[j+1];
+            point pj2 = positions[j+2];
+            point pj3 = positions[j+3];
+
+            point dvp0 = (pi - pj0) * (pi - pj0);
+            point dvp1 = (pi - pj1) * (pi - pj1);
+            point dvp2 = (pi - pj2) * (pi - pj2);
+            point dvp3 = (pi - pj3) * (pi - pj3);
+
+            num d0 = dvp0[0] + dvp0[1] + dvp0[2] + dvp0[3];
+            num d1 = dvp1[0] + dvp1[1] + dvp1[2] + dvp1[3];
+            num d2 = dvp2[0] + dvp2[1] + dvp2[2] + dvp2[3];
+            num d3 = dvp3[0] + dvp3[1] + dvp3[2] + dvp3[3];
+
+            targets[i][j+0] = (typeof(**targets)) { d0, j+0 };
+            targets[i][j+1] = (typeof(**targets)) { d1, j+1 };
+            targets[i][j+2] = (typeof(**targets)) { d2, j+2 };
+            targets[i][j+3] = (typeof(**targets)) { d3, j+3 };
+        }
+        // sort targets. slow.
+        qsort(targets[i], pointcount, sizeof(**targets), targetcompar);
+    }
+    // set up initial next targets
+    for (num i = 0; i < pointcount; i++) {
+        next_targets[i] = targets[i][1].min_target;
+        next_dists[i]   = targets[i][1].min_dist;
+        next_indices[i] = 1;
+    }
+
+    unsigned last_i = 0, last_j = 0;
+    // main iterations
+    do {
+        // find min dist
+        num min_dist = -1;
+        num min_i = 0;
+        for (num i = 0; i < pointcount; i++)
+            if (next_dists[i] < min_dist)
+                min_dist = next_dists[min_i = i];
+        num min_j = next_targets[min_i];
+        last_i = min_i;
+        last_j = min_j;
+        // -- join the pair --
+#if DBG
+        point ipos = positions[min_i];
+        point jpos = positions[min_j];
+        printd(ipos[0]); print(","); printd(ipos[1]); print(","); printd(ipos[2]);
+        print("\t->\t");
+        printd(jpos[0]); print(","); printd(jpos[1]); print(","); printd(jpos[2]);
+        pnl();
+#endif
+        // update circuits
+        unsigned old_circuit = circuits[min_j];
+        unsigned new_circuit = circuits[min_i];
+        if (old_circuit != new_circuit) {
+            bool done = true;
+            for (num c = 0; c < pointcount; c++) {
+                if (circuits[c] == old_circuit)
+                    circuits[c] = new_circuit;
+                if (circuits[c] != new_circuit)
+                    done = false;
+            }
+            if (done) break;
+        }
+        // update targets
+        unsigned niidx = ++next_indices[min_i];
+        unsigned njidx = ++next_indices[min_j];
+        next_targets[min_i] = targets[min_i][niidx].min_target;
+        next_targets[min_j] = targets[min_j][njidx].min_target;
+        next_dists[min_i] = targets[min_i][niidx].min_dist;
+        next_dists[min_j] = targets[min_j][njidx].min_dist;
+    } while(true);
+
+    return positions[last_i][0] * positions[last_j][0];
+}
+
+#define RUN_TEST1 1
+#define RUN_PART1 1
+#define RUN_TEST2 1
+#define RUN_PART2 1
+
+#define TEST1_EXPECT 40
+#define TEST2_EXPECT 25272
+
+void run() {
+#if RUN_TEST1
+    print("PART 1 TEST: ");
+    if (num v = do_part1(countof(test), test, true); 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, false));
+    print("\n");
+#endif
+
+#if RUN_TEST2
+    print("PART 2 TEST: ");
+    if (num v = do_part2(countof(test), test, true); 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, false));
+    print("\n");
+#endif
+
+    exit_group(0);
+}

lib.h

@@ -9,14 +9,6 @@
 
 #define STDOUT_FILENO 1
 
-__attribute__((always_inline))
-void *memchr(const void *s, int c, size_t n) {
-    uint64_t dispose;
-    void *d;
-    asm("repnz scasb":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
-    return d;
-}
-
 static
 void write(uint64_t fileno, void *buffer, size_t len) {
     uint64_t a,d;
@@ -45,6 +37,36 @@ typedef uint64_t bcdint;
 typedef uint64_t num;
 typedef unsigned char ch;
 
+__attribute__((always_inline)) inline
+ch *findc(const ch *s, ch c, size_t n) {
+    uint64_t dispose;
+    void *d;
+    asm("repnz scasb":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
+    return d;
+}
+
+__attribute__((always_inline)) inline
+num *findnum(const num *s, num c, size_t n) {
+    uint64_t dispose;
+    void *d;
+    asm("repnz scasq":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
+    return d;
+}
+
+__attribute__((always_inline)) inline
+num *findnotnum(const num *s, num c, size_t n) {
+    uint64_t dispose;
+    void *d;
+    asm("repz scasq":"=D"(d),"=c"(dispose):"D"(s),"c"(n),"a"(c):"memory","cc");
+    return d;
+}
+
+static inline num alignnum(num v, num align) {
+    num extra = v % align;
+    num adjust = (align - extra) % align;
+    return v + adjust;
+}
+
 static
 void printns(size_t len, unsigned char chars[len]) {
     write(STDOUT_FILENO, chars, len);
@@ -72,6 +94,7 @@ void print_many_char(size_t len, char chars[len]) {
 }
 
 #define print(string) print_many_char(sizeof(string)-1, string)
+#define pnl() print("\n")
 
 static
 void printd(unsigned long v) {