day 01

.gitignore

@@ -0,0 +1,2 @@
+solution
+

01/01.c

@@ -0,0 +1,106 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+int calibration_value_mode1(char * s) {
+  int l = strlen(s);
+
+  int i = 0;
+  int j = l-1;
+
+  while ( !isdigit(s[i]) ) i++;
+  while ( !isdigit(s[j]) ) j--;
+
+  return 10 * (s[i] - '0') + (s[j] - '0');
+}
+
+
+const char * NUMBERS[] = {
+  "one",
+  "two",
+  "three",
+  "four",
+  "five",
+  "six",
+  "seven",
+  "eight",
+  "nine",
+};
+
+
+int str_digit(char * s) {
+  for(int i=0; i<9; i++) {
+    if ( strncmp(NUMBERS[i], s, strlen(NUMBERS[i])) == 0 ) {
+      return i + 1;
+    }
+  }
+
+  return -1;
+}
+
+
+int calibration_value_mode2(char * s) {
+  int l = strlen(s);
+
+  int i = 0;
+  int d1 = 0;
+  int d2 = 0;
+  int tmp;
+
+  while ( i < l ) {
+    if ( isdigit(s[i]) ) {
+      d1 = s[i] - '0';
+      break;
+    }
+    else {
+      d1 = str_digit(&s[i]);
+      if (d1 != -1) break;
+    }
+
+    i++;
+  }
+
+  while ( i < l ) {
+    if ( isdigit(s[i]) ) {
+      d2 = s[i] - '0';
+    }
+    else {
+      tmp = str_digit(&s[i]);
+      if (tmp != -1) {
+        d2 = tmp;
+      }
+    }
+
+    i++;
+  }
+
+  return 10 * d1 + d2;
+}
+
+
+int main(int argc, char* argv[]) {
+  if (argc < 2) {
+    printf("Usage: %s input.txt\n", argv[0]);
+    return 1;
+  }
+
+  int mode = 1;
+  if (argc > 2) {
+    mode = atoi(argv[2]);
+  }
+
+  FILE * f = fopen(argv[1], "r");
+  char s[255];
+
+  int result = 0;
+  do {
+    fscanf(f, "%s\n", s);
+    result += (mode == 1) ? calibration_value_mode1(s) : calibration_value_mode2(s);
+  } while (!feof(f));
+
+  printf("Answer: %d\n", result);
+
+  return 0;
+}

01/Makefile

@@ -0,0 +1,12 @@
+all: tests run
+
+solution: 01.c
+	cc 01.c -Wall -Wextra -o solution
+
+run: solution
+	./solution input.txt 1
+	./solution input.txt 2
+
+tests: solution
+	./solution example1.txt
+	./solution example2.txt 2

01/example1.txt

@@ -0,0 +1,4 @@
+1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet

01/example2.txt

@@ -0,0 +1,7 @@
+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen