second

numbers/tolongn.c

@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct{
+	char *dig;
+	int n;
+	char sign;
+} LongN;
+
+LongN getLongN(char * s);
+void printLong(LongN x); 
+int main() {
+	LongN a;
+	a.dig = (char*)calloc(101, sizeof(char));
+	a.dig[0] = 12;
+	a.dig[1] = 34;
+	a.dig[2] = 5;
+	a.n = 5;
+	a.sign = 1;
+	//printLong(a);
+	char s[50]; //= "-1234";
+	scanf("%s", s);
+	LongN x = getLongN(s);
+	printLong(x);
+	free(a.dig);
+	free(x.dig);
+	return 0;
+}
+
+void printLong(LongN x) {
+	if (x.sign) {
+		printf("-");
+	}
+	if (x.n % 2) {
+		x.n++;
+	}
+	for (int i = 0; i < (int)(x.n/2); ++i) {
+		printf("%d", x.dig[i]);
+	}
+	printf("\n");
+}
+
+LongN getLongN(char* s) {
+	int k = 0;
+	LongN r;
+
+	r.sign = 0;
+	if (s[0] == '-') {
+		k = 1;
+		r.sign = 1;
+	}
+	if (s[0] == '+')
+		k = 1;
+
+	int l = k;
+
+	for (; s[l] >= '0' && s[l] <= '9'; ++l);
+	r.n = (l - k - 1) / 2 + 1;
+	r.dig = (char*)calloc(101, sizeof(char));
+
+	int t = 0;
+	for (int i = l - 1; i >= k; i -= 2, t++) {
+		if (i == k) {
+			r.dig[t] = s[i] - '0';
+		}
+		else 
+			r.dig[t] = 10 * (s[i - 1] - '0') + s[i] - '0';
+	}
+	return r;
+}