Music Problem

题目链接:https://ac.nowcoder.com/acm/contest/5203

题意简化一下就是让我们在数组中找出一组子序列的和为3600的倍数

想法:

我们不妨考虑下 dp 的做法 (但是好像不是官方的正解)

我们设 dp[i] 代表  % 3600 之后结果为 i 的序列的个数

我们考虑转移方程

dp[(j + a[i]) % 3600] = dp[(j + a[i]) % 3600] + 1

但是要注意这里能转移过去的前提是序列的和可以为 j 

#pragma GCC optimize(3,"Ofast","inline")//O3优化
#pragma GCC optimize(2)//O2优化
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <map>
#include <stack>
#include <set>
#include <queue>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <ctime>
#include <bitset>
#include <cmath>
#include <sstream>
#include <iostream>

#define LL long long
#define ls nod<<1
#define rs (nod<<1)+1
#define pii pair<int,int>
#define mp make_pair
#define pb push_back
#define INF 0x3f3f3f3f
#define max(a,b) (a>b?a:b)
#define min(a,b) (a<b?a:b)

const double eps = 1e-10;
const int maxn = 1e5 + 10;
const int mod = 10;

int sgn(double a){return a < -eps ? -1 : a < eps ? 0 : 1;}
using namespace std;

int a[maxn],f[maxn],temp[maxn];
int main() {
    int T;
    cin >> T;
    while (T--) {
        int n;
        cin >> n;
        for (int i = 0;i <= 3600;i++) {
            f[i] = 0;
            temp[i] = 0;
        }
        for (int i = 1;i <= n;i++)
            cin >> a[i];
        for (int i = 1;i <= n;i++) {
            for (int j = 0;j < 3600;j++) {
                if (j == 0 || temp[j] != 0)
                    f[(j + a[i]) % 3600] = f[(j + a[i]) % 3600] + 1;
                if (f[0] > 0) {
                    break;
                }
            }
            if (f[0] > 0)
                break;
            for (int j = 0;j < 3600;j++)
                temp[j] = f[j];
        }
        if (f[0] > 0)
            cout << "YES" << endl;
        else
            cout << "NO" << endl;
    }
    return 0;
}
原文地址:https://www.cnblogs.com/-Ackerman/p/12818361.html