Submission #90757

#	Time	Username	Problem	Language	Result	Execution time	Memory
90757		Vinhspm	Calvinball championship (CEOI15_teams)	C++14	100 / 100	511 ms	1044 KiB

teams

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

#define fi first
#define se second
#define FOR(a, b, c) for(int a = b; a <= c; ++a)
#define pb push_back

const int N = 1e4 + 5;
const int mod = 1e6 + 7;

int n, num;
int a[N], cnt[N];
int f[2][N];

void add(int &x, int y) { x = (x + y) % mod; }
signed main()
{
    scanf("%d", &n);
    FOR(i, 1, n)    {
        scanf("%d", &a[i]), cnt[ a[i] ] ++;
        if(cnt[ a[i] ] == 1) num ++;
    }

    int sum = 1, las = 0, nex = 1;
    FOR(i, 0, n) f[las][i] = 1;

    for(int i = n; i >= 1; --i)     {
        FOR(j, 0, i) {
            add(f[nex][j], 1ll * f[las][j] * 1ll * j % mod);
            add(f[nex][j], f[las][j + 1]);
        }
        cnt[ a[i] ] --; if(cnt[ a[i] ] == 0) num --;
        FOR(t, 1, a[i] - 1) {
            cnt[t] ++; if(cnt[t] == 1) num ++;
            add(sum, f[las][num]);
            cnt[t] --; if(cnt[t] == 0) num --;
        }

        swap(nex, las);
        FOR(j, 0, i) f[nex][j] = 0;
    }

    printf("%d", sum);
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
teams.cpp:21:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &a[i]), cnt[ 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