Submission #5920

#	Time	Username	Problem	Language	Result	Execution time	Memory
5920		baneling100	지우개 (GA4_eraser)	C++98	22 / 100	16 ms	3432 KiB

eraser

#include <stdio.h>
#define MOD 1000000007

long long N, A[100001], M, B[100001], C[100001], Ans;

void input(void)
{
    int i;
    long long temp;

    scanf("%lld",&N);
    for(i=1 ; i<=N ; i++)
    {
        scanf("%lld",&temp);
        C[i]=temp;
        B[temp]=1;
        A[temp]+=temp;
        A[temp]%=MOD;
        if(M<temp)
            M=temp;
    }
    for(i=M-1 ; i>=1 ; i--)
    {
        A[i]+=A[i+1];
        A[i]%=MOD;
    }
    for(i=1 ; i<=M ; i++)
        if(B[i])
        {
            B[i]=i*A[i+1];
            B[i]%=MOD;
        }
    for(i=M-1 ; i>=1 ; i--)
    {
        B[i]+=B[i+1];
        B[i]%=MOD;
    }
}

void process(void)
{
    int i;

    for(i=1 ; i<=N ; i++)
    {
        Ans+=C[i]*B[C[i]+1];
        Ans%=MOD;
    }
}

void output(void)
{
    printf("%lld",Ans);
}

int main(void)
{
    input();
    process();
    output();

    return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 0 / 7
• Subtask 3: 16 / 16
• Subtask 4: 0 / 17
• Subtask 5: 0 / 26
• Subtask 6: 0 / 28