Submission #303339

#	Time	Username	Problem	Language	Result	Execution time	Memory
303339		Ruxandra985	Fancy Fence (CEOI20_fancyfence)	C++14	100 / 100	42 ms	5368 KiB

fancyfence

#include <bits/stdc++.h>
#define MOD 1000000007
#define DIMN 100010
using namespace std;

long long h[DIMN] , w[DIMN] , st[DIMN];
long long spw[DIMN];

long long rectangles (long long x , long long y){
    x %= MOD;
    y %= MOD;
    return ( ( (x * (x + 1) / 2)%MOD ) * ( (y * (y + 1) / 2)%MOD ) )%MOD;

}
int main()
{
    FILE *fin = stdin;
    FILE *fout = stdout;
    long long n , i , elem = 0;
    long long sol = 0 , lat;
    fscanf (fin,"%lld",&n);
    for (i = 1 ; i <= n ; i++)
        fscanf (fin,"%lld",&h[i]);
    for (i = 1 ; i <= n ; i++){
        fscanf (fin,"%lld",&w[i]);

        spw[i] = w[i] + spw[i - 1];

    }

    h[n + 1] = 0; /// turn fictiv inaltime ft mica
    w[n + 1] = 0;
    spw[n + 1] = spw[n];
    n++;

    elem = 0;
    for (i = 1 ; i <= n ; i++){

        while (elem && h[i] <= h[st[elem]]){

            /// i il scoate pe st[elem]
            lat = spw[i - 1] - spw[st[elem - 1]];

            sol = (sol + rectangles(h[st[elem]] , lat) - rectangles (max(h[st[elem - 1]] , h[i]) , lat))%MOD;

            elem--;
        }

        st[++elem] = i;


    }

    sol = ((sol + MOD)%MOD);

    fprintf (fout,"%lld",sol);
    return 0;
}

Compilation message (stderr)

fancyfence.cpp: In function 'int main()':
fancyfence.cpp:21:12: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |     fscanf (fin,"%lld",&n);
      |     ~~~~~~~^~~~~~~~~~~~~~~
fancyfence.cpp:23:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |         fscanf (fin,"%lld",&h[i]);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~
fancyfence.cpp:25:16: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |         fscanf (fin,"%lld",&w[i]);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 18 / 18
• Subtask 7: 27 / 27