roman -> arabic

1 files changed, 69 insertions, 0 deletions

diff --git a/snc.c b/snc.c
new file mode 100644
index 0000000..723e64f
--- /dev/null
+++ b/snc.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+
+#include "snc.h"
+
+int getRomanValue(char symbol)
+{
+	switch(symbol) {
+		case 'I': return SNC_ROMAN_I; // have triple notation
+		case 'V': return SNC_ROMAN_V;
+		case 'X': return SNC_ROMAN_X; // have triple notation
+		case 'L': return SNC_ROMAN_L;
+		case 'C': return SNC_ROMAN_C; // have triple notation
+		case 'D': return SNC_ROMAN_D;
+		case 'M': return SNC_ROMAN_M; // have triple notation
+	}
+	return 0;
+}
+
+int romanToArabic(char *str)
+{
+	int answer = 0;
+	int last_value = 0;
+	int amount_char = 0;
+	while(*str)
+	{
+		int cur_value = getRomanValue(*str);
+		if(cur_value == 0)
+			return -1;
+		else if(last_value == cur_value || last_value == 0) {
+			answer += cur_value;
+			amount_char++;
+		}
+		else if(last_value > cur_value) {
+			answer += cur_value;
+			amount_char = 1;
+		}
+		else if(last_value < cur_value) {
+			answer += cur_value - 2 * last_value;
+			if(amount_char > 1) return -1;
+			amount_char = 1;
+		}
+		last_value = cur_value;
+
+		if(amount_char > 3)
+			return -1;
+		else if(cur_value == SNC_ROMAN_V ||
+				cur_value == SNC_ROMAN_L || cur_value == SNC_ROMAN_D) {
+			if(amount_char > 1) return -1;
+		}
+
+		str++;
+	}
+
+	return answer;
+}
+
+int main(int argc, char *argv[])
+{
+	if(argc < 2)
+		return printf("Simple numbers converter\n"
+					"\n"
+					"Synopsis: snc [number]\n");
+
+	int answer = romanToArabic(argv[1]);
+	if(answer == -1) printf("ERROR! %s is not roman number\n", argv[1]);
+	else printf("answer: %d\n", answer);
+
+	return 0;
+}
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