Submission #457824

#	Time	Username	Problem	Language	Result	Execution time	Memory
457824		vanic	Calvinball championship (CEOI15_teams)	C++14	100 / 100	972 ms	472 KiB

teams

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>

using namespace std;

typedef long long ll;

const int maxn=1e4+5, mod=1e6+7, Log=20;


int n;
int dp[2][maxn];

inline int sum(int a, int b){
	if(a+b>=mod){
		return a+b-mod;
	}
	if(a+b<0){
		return a+b+mod;
	}
	return a+b;
}

inline int mul(int a, int b){
	return (ll)a*b%mod;
}

int a[maxn];
int pref[maxn];

int main(){
	scanf("%d", &n);
	for(int i=0; i<n; i++){
		scanf("%d", a+i);
	}
	int sol=1;
	bool tren=0;
	for(int i=0; i<maxn; i++){
		dp[1][i]=1;
	}
	pref[0]=1;
	for(int i=0; i<n; i++){
		pref[i+1]=max(pref[i], a[i]);
	}
	for(int i=n-1; i>-1; i--){
		sol=sum(sol, mul(a[i]-1, dp[tren^1][pref[i]]));
		for(int j=0; j<maxn-1; j++){
			dp[tren][j]=sum(mul(j, dp[tren^1][j]), dp[tren^1][j+1]);
		}
		tren^=1;
	}
	printf("%d\n", sol);
	return 0;
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:34:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
teams.cpp:36:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |   scanf("%d", a+i);
      |   ~~~~~^~~~~~~~~~~

• 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