Find a multiple
Time Limit: 1000MS | Memory Limit: 65536K | |||
Total Submissions: 4984 | Accepted: 2157 | Special Judge |
Description
The input contains N natural (i.e. positive integer) numbers ( N <= 10000 ). Each of that numbers is not greater than 15000. This numbers are not necessarily different (so it may happen that two or more of them will be equal). Your task is to choose a few of given numbers ( 1 <= few <= N ) so that the sum of chosen numbers is multiple for N (i.e. N * k = (sum of chosen numbers) for some natural number k).
Input
The first line of the input contains the single number N. Each of next N lines contains one number from the given set.
Output
In case your program decides that the target set of numbers can not be found it should print to the output the single number 0. Otherwise it should print the number of the chosen numbers in the first line followed by the chosen numbers themselves (on a separate line each) in arbitrary order.
If there are more than one set of numbers with required properties you should print to the output only one (preferably your favorite) of them.
If there are more than one set of numbers with required properties you should print to the output only one (preferably your favorite) of them.
Sample Input
5 1 2 3 4 1
Sample Output
2 2 3
Source
#include <stdio.h> int main() { int a[10010],mod[10010],ts[10010]; int n,i,j,k,st,ed; scanf("%d",&n); mod[0]=0; memset(ts,0,sizeof(ts)); ts[0]=1; for (i=1;i<=n;i++) { scanf("%d",&a[i]); mod[i]=(mod[i-1]+a[i])%n; ts[mod[i]]++; } k=-1; for (i=0;i<n;i++) if (ts[i]>=2) { k=i; break; } if (k==-1) printf("0\n"); else { for (i=0;i<=n;i++) if (mod[i]==k) { st=i+1; break; } for (i=st;i<=n;i++) if (mod[i]==k) { ed=i; break; } printf("%d\n",ed-st+1); for (i=st;i<=ed;i++) printf("%d\n",a[i]); } return 0; }
因为题目要求只要符合条件就行,所以我的程序虽然与样例不同,但依然AC。
组合数学的抽屉原理,大概思路就是将找前i项和s[i]与前j项和s[j],使得s[i]%n==s[j]%n,那么输出a[i+1]到a[j]即可