Submission #83425

#	Time	Username	Problem	Language	Result	Execution time	Memory
83425		Tusk	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	3 ms	1056 KiB

numbers

#include <bits/stdc++.h>

using namespace std;

long long a, b, ans;
long long dp[20][15][15][2][2];
char A[20];

long long solve(int pos = 0, int a = 10, int b = 10, int f = 0, int st = 1) {
	if(!A[pos]) return 1LL;
	long long &ret = dp[pos][a][b][f][st];
	if(~ret) return ret;
	ret = 0;
	int lim;
	if(!f) lim = A[pos]-'0';
	else lim = 9;
	for(int i = 0; i <= lim; i++) {
		if(i == a || i == b) continue;
		if(!i && st) ret += solve(pos+1, 10, 10, 1, 1);
		else ret += solve(pos+1, b, i, f|(i < lim), 0);
	}

	return ret;
}

int main() {
	scanf("%lld %lld", &a, &b);
	memset(dp, -1LL, sizeof dp);
	sprintf(A, "%lld", b);
	ans = solve();
	if(a) {
		memset(dp, -1LL, sizeof dp);
		sprintf(A, "%lld", a-1);
		ans -= solve();
	}

	printf("%lld\n", ans);

	return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'int main()':
numbers.cpp:27:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld %lld", &a, &b);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~
numbers.cpp:26:5: warning: '__builtin___sprintf_chk' may write a terminating nul past the end of the destination [-Wformat-overflow=]
 int main() {
     ^~~~
In file included from /usr/include/stdio.h:936:0,
                 from /usr/include/c++/7/cstdio:42,
                 from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:46,
                 from numbers.cpp:1:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:34:43: note: '__builtin___sprintf_chk' output between 2 and 21 bytes into a destination of size 20
       __bos (__s), __fmt, __va_arg_pack ());
                                           ^

• Subtask 1: 25 / 25
• Subtask 2: 75 / 75