Submission #244468

#	Time	Username	Problem	Language	Result	Execution time	Memory
244468		cheeheng	Calvinball championship (CEOI15_teams)	C++14	100 / 100	832 ms	632 KiB

teams

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

const int MOD = 1000007;

int A[10005];
int dp[2][10005][2];
int prefixMax[10005];

int n;

/*
int dp(int i, int cur_max, int same_so_far){
    if(i == n){
        return 1;
    }else if(memo[i][cur_max][same_so_far] != -1){
        return memo[i][cur_max][same_so_far];
    }else{
        long long ans = 0;

        if(same_so_far){
            for(int j = 1; j <= A[i]; j ++){
                ans += dp(i+1, max(cur_max, j), j == A[i]);
            }
        }else{
            for(int j = 1; j <= cur_max+1; j ++){
                ans += dp(i+1, max(cur_max, j), 0);
            }
        }

        return memo[i][cur_max][same_so_far] = ans%MOD;
    }
}*/

int main(){
    scanf("%d", &n);

    prefixMax[0] = 0;
    for(int i = 0; i < n; i ++){
        scanf("%d", &A[i]);
        prefixMax[i+1] = max(prefixMax[i], A[i]);
    }

    for(int i = n; i >= 0; i --){
        //long long prefix_sum = dp[(i+1)&1][max(cur_max, 0)][0];
        for(int cur_max = 0; cur_max <= n; cur_max ++){
            for(int same_so_far = 0; same_so_far < 2; same_so_far ++){
                if(i == n){
                    dp[i&1][cur_max][same_so_far] = 1;
                }else{
                    long long ans = 0;

                    if(same_so_far){
                        if(cur_max == prefixMax[i]){
                            for(int j = 1; j <= A[i]; j ++){
                                ans += dp[(i+1)&1][max(cur_max, j)][j == A[i]];
                            }
                        }
                    }else{
                        //prefix_sum += dp[(i+1)&1][max(cur_max, 0)][0];
                        ans = cur_max*(long long)dp[(i+1)&1][cur_max][0] + dp[(i+1)&1][cur_max+1][0];
                        /*for(int j = 1; j <= cur_max+1; j ++){
                            ans += dp[(i+1)&1][max(cur_max, j)][0];
                        }*/
                    }

                    dp[i&1][cur_max][same_so_far] = ans%MOD;
                }
            }
        }
    }

    printf("%d", dp[0][0][1]);
    return 0;
}

Compilation message (stderr)

teams.cpp: In function 'int main()':
teams.cpp:36:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
teams.cpp:40:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         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