【Codeforces】 489C Given Length and Sum of Digits

#include <iostream>
#include <queue> 
#include <stack> 
#include <map> 
#include <set> 
#include <bitset> 
#include <cstdio> 
#include <algorithm> 
#include <cstring> 
#include <climits>
#include <cstdlib>
#include <cmath>
#include <time.h>
#define maxn 1005
#define maxm 200005
#define eps 1e-10
#define mod 1000000007
#define INF 0x3f3f3f3f
#define PI (acos(-1.0))
#define lowbit(x) (x&(-x))
#define mp make_pair
#define ls o<<1
#define rs o<<1 | 1
#define lson o<<1, L, mid 
#define rson o<<1 | 1, mid+1, R
//#pragma comment(linker, "/STACK:16777216")
typedef long long LL;
typedef unsigned long long ULL;
//typedef int LL;
using namespace std;
LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}
LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}
void scanf(int &__x){__x=0;char __ch=getchar();while(__ch==' '||__ch=='\n')__ch=getchar();while(__ch>='0'&&__ch<='9')__x=__x*10+__ch-'0',__ch = getchar();}
LL gcd(LL _a, LL _b){if(!_b) return _a;else return gcd(_b, _a%_b);}
// head

int digit[maxn];
char s1[maxn];
char s2[maxn];
int m, s;

void read(void)
{
	scanf("%d%d", &m, &s);
}

void work(void)
{
	if(m == 1 && s == 0) {
		printf("0 0\n");
		return;
	}
	if(s < 1 || s > m * 9) {
		printf("-1 -1\n");
		return;
	}
	s1[0] = max(s - (m-1) * 9, 1) + '0';
	int now = s - s1[0] + '0';
	for(int i = m-1; i >= 1; i--) {
		if(now > 9) s1[i] = '9', now -= 9;
		else s1[i] = '0' + now, now = 0;
	}
	printf("%s ", s1);
	now = s;
	for(int i = 0; i < m; i++) {
		if(now > 9) s2[i] = '9', now -= 9;
		else s2[i] = '0' + now, now = 0;
	}
	printf("%s\n", s2);
}

int main(void)
{
	read();
	work();

	return 0;
}