C. Given Length and Sum of Digits... (貪心)
https://codeforces.com/problemset/problem/489/C
C. Given Length and Sum of Digits...
You have a positive integer m and a non-negative integer s. Your task is to find the smallest and the largest of the numbers that have length m and sum of digits s. The required numbers should be non-negative integers written in the decimal base without leading zeroes.
Input
The single line of the input contains a pair of integers m, s (1 ≤ m ≤ 100, 0 ≤ s ≤ 900) — the length and the sum of the digits of the required numbers.
Output
In the output print the pair of the required non-negative integer numbers — first the minimum possible number, then — the maximum possible number. If no numbers satisfying conditions required exist, print the pair of numbers "-1 -1" (without the quotes).
Examples
input
2 15
output
69 96
input
3 0
output
-1 -1
題意:
給定一個數m 和 一個長度s,計算最大和最小在s長度下的十進位制各位數和為m的值
注意如果無法生成,即輸出兩個-1
題解:
有個小坑,在輸出最大值時得注意下k 是否為 0
#include<bits/stdc++.h> using namespace std; int main() { int m, s, i, k; cin >> m >> s; if (s < 1 && m>1 || s > m * 9) cout << -1 << " " << -1 << endl; else { for (i = m - 1, k = s; i >= 0; i--) { int j = max(0, k - 9 * i); if (j == 0 && i == m - 1 && k) j = 1; cout << j; k -= j; } cout << ' '; for (i = m - 1, k = s; i >= 0; i--) { int j = min(9, k); cout << j; k -= j; } } }