[HAOI2012]音量调节

题目地址：

https://ac.nowcoder.com/acm/problem/19990

基本思路:

参考代码：

/*
  Author: sunsetcolors
*/
#pragma GCC optimize(2)
#pragma GCC optimize(3)
#include <bits/stdc++.h>
using namespace std;
#define IO std::ios::sync_with_stdio(false); cin.tie(0)
#define ll long long
#define ull unsigned long long
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rep(i, l, r) for (int (i) = l; (i) <= (r); ++(i))
#define per(i, l, r) for (int (i) = l; (i) >= (r); --(i))
#define mset(s, _) memset(s, _, sizeof(s))
#define pb push_back
#define pii pair <int, int>
#define mp(a, b) make_pair(a, b)
#define debug(x) cerr << #x << " = " << (x) << '\n';
#define pll pair <ll, ll>
#define fir firsts
#define sec second
#define INF 0x3f3f3f3f
#define int ll
template<typename T1, typename T2> int gcd(T1 a, T2 b) { return b == 0 ? a : gcd(b,a % b); }
template<typename T1, typename T2> void ckmin(T1 &a, T2 b) { if (a > b) a = b; }
template<typename T1, typename T2> void ckmax(T1 &a, T2 b) { if (a < b) a = b; }
inline int read() {
  int x = 0, f = 0; char ch = getchar();
  while (!isdigit(ch)) f |= ch == '-', ch = getchar();
  while (isdigit(ch)) x = 10 * x + ch - '0', ch = getchar();
  return f ? -x : x;
}
template<typename T> inline void print(T x) {
  if (x < 0) putchar('-'), x = -x;
  if (x >= 10) print(x / 10);
  putchar(x % 10 + '0');
}
template<typename T> inline void print(T x, char let) {
  print(x), putchar(let);
}

const int maxn = 55;
int n,s,t,a[maxn];
bool dp[maxn][1010];
signed main() {
  IO;
  cin >> n >> s >> t;
  rep(i,1,n) cin >> a[i];
  dp[0][s] = true;
  rep(i,1,n) rep(j,0,t) {
      if (j + a[i] <= t) dp[i][j + a[i]] |= dp[i - 1][j];
      if (j - a[i] >= 0) dp[i][j - a[i]] |= dp[i - 1][j];
  }
  int ans = -1;
  per(j,t,0) if(dp[n][j]) { ans = j; break; }
  cout << ans << '\n';
  return 0;
}