challenge passed (ca. 660 ms)

2024/09/s2b.c

+/* with extra datastructures to perform better on evil inputs */
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "inputs.h"
+#include "evil_input.h"
+
+#ifdef INSTD
+#define INPUT argv[1]
+#elif defined(EVIL1)
+#define INPUT somewhat_evil_input
+#elif defined(EVIL2)
+#define INPUT really_evil_input
+#elif !defined(INPUT)
+#define INPUT I
+#endif
+
+#define FREE 0xFFFFFFFFU
+
+struct entry {
+	unsigned int width;
+	unsigned int prev;
+	unsigned int next;
+	unsigned int fno;
+};
+
+#define NI 524288U
+struct entry ent[NI];
+
+unsigned int nextinbucket[NI];
+unsigned int firstinbucket[10] = {
+	FREE, FREE, FREE, FREE, FREE,
+	FREE, FREE, FREE, FREE, FREE,
+};
+
+static void
+chkbucket(int where)
+{
+#ifdef dovis3
+	int i;
+	unsigned int n;
+	int e = 0;
+
+	for (i = 1; i <= 9; ++i) {
+		printf("bucket(%d): ", i);
+		n = firstinbucket[i];
+		while (n != FREE) {
+			if (ent[n].width == i)
+				printf("%u\033[0m ", n);
+			else {
+				printf("\033[5m%u(%u)\033[0m ", n, ent[n].width);
+				e = 1;
+			}
+			if (nextinbucket[n] != FREE &&
+			    nextinbucket[n] <= n) {
+				printf("\033[1m");
+				e = 1;
+			}
+			n = nextinbucket[n];
+		}
+		printf("END\033[0m\n");
+	}
+	printf("chkbucket(%d): %s\n", where, e ? "ERROR" : "ok");
+#endif
+}
+
+int
+main(int argc, char *argv[])
+{
+	size_t i, j, k, fl;
+	unsigned long long curblk, sum, nextblk;
+	unsigned char ch;
+
+#ifdef INSTD
+	if (argc != 2)
+		errx(1, "Usage: ./a.out $(<inputfile)");
+#endif
+
+	i = 0;
+	while ((ch = INPUT[i])) {
+		if (ch < '0' || ch > '9')
+			errx(2, "invalid input char: %02X", (unsigned int)ch);
+		ent[i].width = (unsigned int)ch - (unsigned int)'0';
+		ent[i].prev = i - 1U;
+		ent[i].next = i + 1U;
+		if (i & 1U) {
+			ent[i].fno = FREE;
+		} else {
+			ent[i].fno = i / 2U;
+		}
+		++i;
+	}
+	ent[0].prev = 0;
+	ent[i].width = 0;
+	ent[i].prev = i - 1U;
+	ent[i].next = i;
+	ent[i].fno = FREE;
+	fl = i + 1; /* freelist */
+	j = i--;
+
+#ifdef dovis2
+		j = 0;
+		while (ent[j].next != j) {
+			unsigned int x;
+
+			ch = ent[j].fno == FREE ? '.' : '0' + ent[j].fno;
+			x = ent[j].width;
+			while (x--)
+				putchar(ch);
+			j = ent[j].next;
+		}
+		printf("\n");
+#endif
+
+	do {
+		j -= 2;
+		nextinbucket[j] = firstinbucket[ent[j].width];
+		firstinbucket[ent[j].width] = j;
+	} while (j > 1);
+	chkbucket(0);
+
+	while (i) {
+#ifdef dovis3
+		printf("i(%u) fno(%u) prev(%u)\n",
+		    (unsigned)i, (unsigned)ent[i].fno, (unsigned)ent[i].prev);
+#endif
+		if (ent[i].fno == FREE)
+			goto nexti;
+		j = k = ent[i].width;
+		while (++j <= 9)
+			if (firstinbucket[k] == FREE ||
+			    (firstinbucket[j] != FREE &&
+			     firstinbucket[j] < firstinbucket[k]))
+				k = j;
+		if ((j = firstinbucket[k]) == FREE || j > i)
+			goto nexti;
+		/* move */
+
+		/* free free-bucket */
+		firstinbucket[k] = nextinbucket[j];
+#ifdef dovis3
+		printf("D: taking first (%u) from bucket %u, next is %u\n",
+		    (unsigned)j, (unsigned)k, (unsigned)firstinbucket[k]);
+#endif
+		/* easy move? */
+		if (ent[j].width == ent[i].width) {
+			ent[j].fno = ent[i].fno;
+			ent[i].fno = FREE;
+		} else {
+			ent[fl].width = ent[i].width;
+			ent[fl].prev = ent[j].prev;
+			ent[ent[fl].prev].next = fl;
+			ent[fl].next = j;
+			ent[j].prev = fl;
+			ent[fl].fno = ent[i].fno;
+			ent[i].fno = FREE;
+			ent[j].width -= ent[i].width;
+			if (++fl == NI)
+				errx(1, "out of space");
+			chkbucket(3);
+			/* put at right space in new bucket */
+			if (j < firstinbucket[ent[j].width]) {
+				nextinbucket[j] = firstinbucket[ent[j].width];
+				firstinbucket[ent[j].width] = j;
+				chkbucket(1);
+			} else {
+				k = firstinbucket[ent[j].width];
+				while (nextinbucket[k] < j)
+					k = nextinbucket[k];
+				/* now: k < j < nextinbucket[k] */
+				nextinbucket[j] = nextinbucket[k];
+				nextinbucket[k] = j;
+				chkbucket(2);
+			}
+		}
+#ifdef dovis2
+		j = 0;
+		while (ent[j].next != j) {
+			unsigned int x;
+
+			ch = ent[j].fno == FREE ? '.' : '0' + ent[j].fno;
+			x = ent[j].width;
+			while (x--)
+				putchar(ch);
+			j = ent[j].next;
+		}
+		printf("\n");
+#endif
+ nexti:
+#if 0 /* I used this in s2.c but it can never have worked?! */
+		i = ent[i].prev;
+#else
+		i -= 2;
+#endif
+	}
+
+#ifdef dovis
+	i = 0;
+	while (ent[i].next != i) {
+		unsigned int x;
+
+		ch = ent[i].fno == FREE ? '.' : '0' + ent[i].fno;
+		x = ent[i].width;
+		while (x--)
+			putchar(ch);
+		i = ent[i].next;
+	}
+	printf("\n");
+#endif
+
+	i = 0;
+	curblk = 0;
+	sum = 0;
+	while (ent[i].next != i) {
+		nextblk = curblk + ent[i].width;
+		if (ent[i].fno != FREE) {
+			sum += (nextblk * (nextblk - 1U) - curblk * (curblk - 1U)) / 2U *
+			    ent[i].fno;
+		}
+		curblk = nextblk;
+		i = ent[i].next;
+	}
+	printf("%llu\n", sum);
+	return (0);
+}

2024/09/str

+../../i2c/str
\ No newline at end of file

i2c/str

+#!/bin/mksh
+set -e
+doone() {
+	print -r -- "static const char I[] = \"$(
+		sed 's/[\\"]/\\&/g' <"$1" #'"
+	    )\";"
+}
+exec >inputs.h
+print '#ifndef PROD'
+print
+doone c
+print
+print '#else'
+print
+doone i
+print
+print '#endif'
+exec >/dev/null
+exit 0