Submission #57378

#	Time	Username	Problem	Language	Result	Execution time	Memory
57378		RezwanArefin01	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	4 ms	704 KiB

numbers

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> ii; 

ll dp[20][11][11][2][2]; 
string s; 

ll f(int pos, int a, int b, bool small, bool start) {
	if(pos == s.size()) return 1; 
	ll &ret = dp[pos][a][b][small][start]; 
	if(~ret) return ret; 
	ret = 0; 
	int lim = small ? 9 : s[pos] - '0'; 
	for(int i = 0; i <= lim; i++) {
		if(i == a || i == b) continue; 
		if(!i && start) {
			ret += f(pos + 1, 10, 10, 1, 1); 
		} else {
			ret += f(pos + 1, b, i, small | (i < lim), 0); 
		}
	} return ret; 
}

ll solve(ll n) {
    s = to_string(n); 
    memset(dp, -1, sizeof dp); 
    return f(0, 10, 10, 0, 1); 
}

int main(int argc, char const *argv[]) {
    ll a, b; 
    scanf("%lld %lld", &a, &b); 
    ll ans = solve(b); 
    if(a) ans -= solve(a - 1); 
    printf("%lld\n", ans); 
}

Compilation message (stderr)

numbers.cpp: In function 'll f(int, int, int, bool, bool)':
numbers.cpp:11:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(pos == s.size()) return 1; 
     ~~~~^~~~~~~~~~~
numbers.cpp: In function 'int main(int, const char**)':
numbers.cpp:34:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld %lld", &a, &b); 
     ~~~~~^~~~~~~~~~~~~~~~~~~~~

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