B. Hometasktime limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
Furik loves math lessons very much, so he doesn't attend them, unlike Rubik. But now Furik wants to get a good mark for math. For that Ms. Ivanova, his math teacher, gave him a new task. Furik solved the task immediately. Can you?
You are given a set of digits, your task is to find the maximum integer that you can make from these digits. The made number must be divisible by 2, 3, 5 without
a residue. It is permitted to use not all digits from the set, it is forbidden to use leading zeroes.
Each digit is allowed to occur in the number the same number of times it occurs in the set.
Input
A single line contains a single integer n (1 ≤ n ≤ 100000) —
the number of digits in the set. The second line contains n digits, the digits are separated by a single space.
Output
On a single line print the answer to the problem. If such number does not exist, then you should print -1.
Sample test(s)input
10
output
0
input
113 4 5 4 5 3 5 3 4 4 0
output
5554443330
input
83 2 5 1 5 2 2 3
output
-1
Note
In the first sample there is only one number you can make — 0. In the second sample the sought number is 5554443330. In the third sample it is impossible to make the required number.
這題看似簡單,非常容易漏掉情況沒有考慮。如果餘1,可以刪一個餘數1的,或者兩個餘數2的!如果餘2,可以刪一個餘數2的,或兩個餘數1的。最後注意!如果只有0出現的話,最後只輸出一個0!所以要特判。
#include<cstdio>#include<cstring>#include<queue>#include<vector>#include<algorithm>#include<iostream>#include<string>#include<map>using namespace std;typedef long long LL;const int maxn = 100 + 5;const int INF = 1000000000;int num[10];int main(){ int n; while(cin >> n){ memset(num,0,sizeof(num)); int total = 0; for(int i = 0;i < n;i++){ int tem; cin >> tem; num[tem]++; total += tem; } total = total % 3; int tag = 1; if(total == 1){ tag = 0; for(int i = 0;i < 10;i++){ if(i%3 == 1 && num[i] > 0){ tag = 1; num[i]--; break; } } int cnt = 2; if(tag == 0){ for(int i = 0;i < 10;i++){ while(i%3 == 2 && num[i] > 0 && cnt > 0){ num[i]--; cnt--; } } if(cnt == 0) tag = 1; } } else if(total == 2){ int cnt = 2; tag = 0; for(int i = 0;i < 10;i++){ if(i%3 == 2 && num[i] > 0){ num[i]--; tag = 1; break; } } if(tag == 0){ for(int i = 0;i < 10;i++){ while(i%3 == 1 && num[i] > 0 && cnt > 0){ num[i]--; cnt--; } } if(cnt == 0) tag = 1; } } if(tag == 0 || num[0] == 0){ cout << -1 << endl; continue; } else{ int flag = 0; for(int i = 9;i >= 0;i--){ if(i == 0 && flag == 0){ cout << 0 << endl; break; } while(num[i] > 0){ if(i != 0) flag = 1; num[i]--; cout << i; } } cout << endl; } } return 0;}