1 files changed, 67 insertions, 0 deletions
diff --git a/021.c b/021.c
new file mode 100644
index 0000000..8f0cd09
--- /dev/null
+++ b/021.c
@@ -0,0 +1,67 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <string.h>
+#include "input.h"
+
+#define INPUT "input/02.txt"
+
+enum direction { forward, up, down };
+
+struct submarine_move {
+	enum direction dir;
+	int length;
+};
+
+void parse_move(char* string, struct submarine_move* move) {
+	if(*string == 'f')
+		move->dir = forward;
+	else if(*string == 'u')
+		move->dir = up;
+	else if(*string == 'd')
+		move->dir = down;
+	else
+		err(1, "direction inconnue %c", *string);
+
+	size_t stringLength = strlen(string);
+	char digit = string[stringLength - 2];
+	if(digit < '0' || digit > '9')
+		err(1, "longueur inconnue %c", digit);
+	move->length = digit - '0';
+}
+
+int main() {
+	// lecture du fichier d'entree
+	FILE* file=fopen(INPUT,"r");
+	if(file == NULL)
+		err(1, "Le fichier %s n'existe pas\n", INPUT);
+	
+	size_t lineCount = count_lines(file);
+	char** input = malloc(lineCount * sizeof(char*));
+	read_lines_as_string(file, input, lineCount);
+	// fermeture du fichier
+	fclose(file);
+
+	// l'algo
+	struct submarine_move currentMove;
+	long forwardDst = 0;
+	long downDst = 0;
+	for(size_t i = 0; i < lineCount; i++) {
+		parse_move(input[i], &currentMove);
+		switch(currentMove.dir) {
+			case forward:
+				forwardDst += currentMove.length;
+				continue;
+			case up:
+				downDst -= currentMove.length;
+				continue;
+			case down:
+				downDst += currentMove.length;
+				continue;
+		}
+	}
+	printf("%ld\n", forwardDst * downDst);
+
+	free_strings(input, lineCount);
+	return 0;
+}