CodeForce 577B Modulo Sum
You are given a sequence of numbers a1, a2, ..., an, and a number m.
Check if it is possible to choose a non-empty subsequence aij such that the sum of numbers in this subsequence is divisible by m.
Input
The first line contains two numbers, n and m (1 ≤ n ≤ 106, 2 ≤ m ≤ 103) — the size of the original sequence and the number such that sum should be divisible by it.
The second line contains n integers a1, a2, ..., an (0 ≤ ai ≤ 109).
OutputIn the single line print either "YES" (without the quotes) if there exists the sought subsequence, or "NO" (without the quotes), if such subsequence doesn't exist.
Examples3 5
1 2 3
YES
1 6
5
NO
4 6
3 1 1 3
YES
6 6
5 5 5 5 5 5
YES
In the first sample test you can choose numbers 2 and 3, the sum of which is divisible by 5.
In the second sample test the single non-empty subsequence of numbers is a single number 5. Number 5 is not divisible by 6, that is, the sought subsequence doesn't exist.
In the third sample test you need to choose two numbers 3 on the ends.
In the fourth sample test you can take the whole subsequen
OJ-ID:
CodeForce 577B
author:
Caution_X
date of submission:
20191019
tags:
dp
description modelling:
给一个序列,找一个子序列使之mod m =0
major steps to solve it:
dp[i]:表示取模后得到了i
1.遍历序列,对每一个元素更新dp,判断能否得到dp[0]
AC code:
#include<bits/stdc++.h> using namespace std; typedef long long ll; ll a[1000005],dp[1000005],tmp[1000005]; int main() { ll n,m; scanf("%lld%lld",&n,&m); for(int i=0;i<n;i++) { scanf("%lld",&a[i]); } for(int i=0;i<n;i++) { if(dp[0]) break; for(int j=0;j<=m-1;j++) { if(dp[j]) { tmp[(j+a[i])%m]=1; } } tmp[a[i]%m]=1; for(int j=0;j<=m-1;j++) { dp[j]=tmp[j]; } } if(dp[0]) printf("YES\n"); else printf("NO\n"); return 0; }