any

numbers/any.c

@@ -0,0 +1,60 @@
+#include <stdio.h>
+#include <math.h>
+#include <string.h>
+
+int to_dec(char *s, int n);
+void to_n(int x, int n, char *res);
+void print_reverse(char *s);
+
+int main() {
+	int n, k;
+	char A[1000];
+	char res[1000] = "";
+	scanf("%d\n%s\n%d", &n, A, &k);
+	if ((strlen(A) == 1) && (A[0] == '0')) {
+		printf("0\n");
+		return 0;
+	}
+	n = to_dec(A, n);
+	to_n(n, k, res);
+	print_reverse(res);
+	return 0;
+}
+
+void to_n(int x, int n, char *res) {
+	int a, b;
+	int i;
+	a = x;
+	for (i = 0; a > 0; ++i) {
+		b = a % n;
+		a = (int)(a / n);
+		if (b < 10) {
+			res[i] = '0' + b;
+		}
+		else {
+			res[i] = 'A' + b - 10;
+		}
+	}
+	res[i] = '\0';
+}
+
+int to_dec(char *s, int n) {
+	int len = strlen(s);
+	int res = 0;
+	for (int i = len - 1; i >= 0; --i) {
+		if (s[i] >= '0' && s[i] <= '9') {
+			res += (s[i] - '0') * pow(n, len-i-1);
+		}
+		else {
+			res += (s[i] - 'A' + 10) * pow(n, len-i-1);
+		}
+	}
+	return res;
+}
+
+void print_reverse(char *s) {
+	for (int i = strlen(s) - 1; i >= 0; --i) {
+		printf("%c", s[i]);
+	}
+	putchar('\n');
+}