Submission #412445

#	Time	Username	Problem	Language	Result	Execution time	Memory
412445		Ozy	Foehn Phenomena (JOI17_foehn_phenomena)	C++17	100 / 100	237 ms	16792 KiB

foehn_phenomena

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for (int i = (a); i <= (b); i++)
#define repa(i,a,b) for (int i = (a); i >= (b); i--)
#define lli long long int
#define debug(a) cout << #a << " = " << a << endl
#define debugsl(a) cout << #a << " = " << a << ", "

#define tam 200002
#define alt(x) (arr[x] + query(x))

lli BIT[tam],arr[tam],ST[(1<<19)+2];
lli n,q,s,t,a,b,l,r,c,offset,d;

void agrega(lli pos, lli val) {
    while (pos < tam) {
        BIT[pos] += val;
        pos += pos&(-pos);
    }
}

lli query(lli pos) {
    lli res = 0;
    while (pos > 0) {
        res += BIT[pos];
        pos -= pos&(-pos);
    }
    return res;
}

void actualiza(lli nodo, lli val) {
    lli mitad,a,b;

    ST[nodo] = val;
    nodo /= 2;
    while (nodo > 0) {
        ST[nodo] = ST[nodo*2] + ST[(nodo*2)+1];
        nodo /= 2;
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> q >> s >> t;
    rep(i,0,n) cin >> arr[i];
    s *= -1;

    offset = 1;
    while (offset < n) offset<<=1;
    rep(i,0,n-1) {
        a = arr[i];
        b = arr[i+1];

        c = (a<b)? (b-a)*s : (a-b)*t;
        ST[offset+i] = c;
    }
    repa(i,offset-1,1) ST[i] = ST[i<<1] + ST[(i<<1)+1];

    rep(i,1,q) {
        cin >> l >> r >> c;
        agrega(l,c);
        agrega(r+1,-c);

        a = alt(l-1);
        b = alt(l);
        c = (a<b)? (b-a)*s : (a-b)*t;
        actualiza(l+offset-1, c);

        if (r < n) {
            a = alt(r);
            b = alt(r+1);
            c = (a<b)? (b-a)*s : (a-b)*t;
            actualiza(r+offset, c);
        }

        cout << ST[1] << "\n";
    }

    return 0;
}

Compilation message (stderr)

foehn_phenomena.cpp: In function 'void actualiza(long long int, long long int)':
foehn_phenomena.cpp:33:9: warning: unused variable 'mitad' [-Wunused-variable]
   33 |     lli mitad,a,b;
      |         ^~~~~
foehn_phenomena.cpp:33:15: warning: unused variable 'a' [-Wunused-variable]
   33 |     lli mitad,a,b;
      |               ^
foehn_phenomena.cpp:33:17: warning: unused variable 'b' [-Wunused-variable]
   33 |     lli mitad,a,b;
      |                 ^

• Subtask 1: 30 / 30
• Subtask 2: 10 / 10
• Subtask 3: 60 / 60