Submission #854402

#	Time	Username	Problem	Language	Result	Execution time	Memory
854402		pliam	Fancy Fence (CEOI20_fancyfence)	C++17	12 / 100	122 ms	262144 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
#define MAXN 100005
typedef long long ll;
#define MOD (ll)1e9+7
#define INF (ll)2e9
/*
Brute force N^4
*/
int N, L;
ll h[MAXN], w[MAXN];
vector<ll> nh;
int main(){
    scanf("%d",&N);
    for(int i=0;i<N;i++){
        scanf("%lld",&h[i]);
    }
    for(int i=0;i<N;i++){
        scanf("%lld",&w[i]);
        for(int j=0;j<w[i];j++){
            L++;
            nh.push_back(h[i]);
        }
    }
    ll ans=0;
    for(int i=0;i<L;i++){
        // printf("%lld\n", nh[i]);
        for(int j=0; j<=i; j++){
            //[j,i], find minimum m and answer is m*(m+1)/2
            ll m=INF;
            for(int k=j;k<=i;k++){
                m = min(m, nh[k]);
            }
            ans += (m*(m+1))/2LL;
            ans %= MOD;
        }
    }
    printf("%lld\n", ans);
}

Compilation message (stderr)

fancyfence.cpp: In function 'int main()':
fancyfence.cpp:14:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     scanf("%d",&N);
      |     ~~~~~^~~~~~~~~
fancyfence.cpp:16:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |         scanf("%lld",&h[i]);
      |         ~~~~~^~~~~~~~~~~~~~
fancyfence.cpp:19:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         scanf("%lld",&w[i]);
      |         ~~~~~^~~~~~~~~~~~~~

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