제출 #438684

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
438684		peijar	Skyscraper (JOI16_skyscraper)	C++17	100 / 100	646 ms	316848 KiB

skyscraper

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int MOD = 1e9 + 7;
int lenPerm, maxSum;

int dp[100][1001][101][2][2];
// dp[curPos][curSum][ccCenter][fL][fR];
int diffs[101];

void iterative() {
  for (int curPos = lenPerm - 1; curPos >= 0; --curPos)
    for (int _curSum = 0; _curSum <= maxSum; ++_curSum)
      for (int ccCenter = 0; ccCenter <= lenPerm; ++ccCenter)
        for (int fL = 0; fL < 2; ++fL)
          for (int fR = 0; fR < 2; ++fR) {
            int &cur = dp[curPos][_curSum][ccCenter][fL][fR];
            cur = 0;

            int curSum = _curSum;
            curSum += fL * diffs[curPos];
            curSum += fR * diffs[curPos];
            curSum += ccCenter * diffs[curPos] * 2;
            if (curSum > maxSum)
              continue;

            if (curPos == lenPerm - 1) {
              if (ccCenter > 0 or (!fL and !fR))
                continue;
              cur = 1;
              continue;
            }

            // Create new cc :
            if (ccCenter < lenPerm)
              cur += dp[curPos + 1][curSum][ccCenter + 1][fL][fR];
            // Create new cc on side :
            if (!fL)
              cur += dp[curPos + 1][curSum][ccCenter][true][fR];
            if (!fR)
              cur += dp[curPos + 1][curSum][ccCenter][fL][true];
            // merge center and side :
            if (fL and ccCenter)
              cur += ccCenter * dp[curPos + 1][curSum][ccCenter - 1][true][fR];
            if (fR and ccCenter)
              cur += ccCenter * dp[curPos + 1][curSum][ccCenter - 1][fL][true];
            // merge centers :
            if (ccCenter >= 2)
              cur += ccCenter * (ccCenter - 1) *
                     dp[curPos + 1][curSum][ccCenter - 1][fL][fR];
            // add to center :
            if (ccCenter)
              cur += 2 * ccCenter * dp[curPos + 1][curSum][ccCenter][fL][fR];
            // add to side:
            if (fL)
              cur += dp[curPos + 1][curSum][ccCenter][fL][fR];
            if (fR)
              cur += dp[curPos + 1][curSum][ccCenter][fL][fR];
            // Add to center and merge with side :
            if (!fL and ccCenter)
              cur += ccCenter * dp[curPos + 1][curSum][ccCenter - 1][true][fR];
            if (!fR and ccCenter)
              cur += ccCenter * dp[curPos + 1][curSum][ccCenter - 1][fL][true];
            cur %= MOD;
          }
}

signed main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  cin >> lenPerm >> maxSum;
  for (int i = 0; i < lenPerm; ++i) {
    cin >> diffs[i];
  }
  sort(diffs, diffs + lenPerm);
  for (int i = lenPerm - 1; i > 0; --i)
    diffs[i] -= diffs[i - 1];
  if (lenPerm == 1) {
    cout << 1 << endl;
    return 0;
  }
  iterative();
  cout << dp[0][0][0][0][0] << endl;
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80