Submission #259435

#	Time	Username	Problem	Language	Result	Execution time	Memory
259435		ChrisT	Calvinball championship (CEOI15_teams)	C++17	100 / 100	127 ms	564 KiB

teams

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
const int MN = 1e4 + 5, LOG = 18, MOD = 1e6 + 7;
int dp2[2][MN], a[MN], mx[MN];
int main () {
	int n, ans = 1;
	scanf ("%d",&n);
	for (int i = 1; i <= n; i++) scanf ("%d",&a[i]), mx[i] = max(mx[i-1],a[i-1]);
	for (int j = 1; j <= n; j++) dp2[n&1][j] = 1;
	for (int i = n; i >= 1; i--) {
		if (i<n)
		for (int j = 1; j <= i; j++) {
			dp2[i&1][j] = (dp2[i&1^1][j+1] + (ll)dp2[i&1^1][j] * j) % MOD;
		}
		ans = (ans + (ll)(a[i]-1)*dp2[i&1][mx[i]]) % MOD;
	}
	printf ("%d\n",ans);
	return 0;
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:15:24: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
    dp2[i&1][j] = (dp2[i&1^1][j+1] + (ll)dp2[i&1^1][j] * j) % MOD;
                       ~^~
teams.cpp:15:46: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
    dp2[i&1][j] = (dp2[i&1^1][j+1] + (ll)dp2[i&1^1][j] * j) % MOD;
                                             ~^~
teams.cpp:9:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d",&n);
  ~~~~~~^~~~~~~~~
teams.cpp:10:49: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for (int i = 1; i <= n; i++) scanf ("%d",&a[i]), mx[i] = max(mx[i-1],a[i-1]);
                               ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10