Submission #924891

#	Time	Username	Problem	Language	Result	Execution time	Memory
924891		niter	Foehn Phenomena (JOI17_foehn_phenomena)	C++14	100 / 100	83 ms	13140 KiB

foehn_phenomena

#include <bits/stdc++.h>
#define loop(i,a,b) for(int i = (a); i < (b); i ++)
using namespace std;
typedef long long ll;

const int mxn = 200005;
ll S, T;
ll a[mxn], b[mxn];

ll cal(ll pre, ll nxt){
    if(nxt > pre) return (-S) * abs(nxt - pre);
    else return T * abs(pre - nxt);
}

ll cal(ll det){
    if(det > 0) return (-S) * abs(det);
    else return T * abs(det);
}

int main(){
    ios::sync_with_stdio(false); cin.tie(0);
//    freopen("in.txt", "r", stdin);
    int n, q; cin >> n >> q;
    cin >> S >> T;
    // S: decrease (go up), T: increase (go down)
    loop(i,0,n+1) cin >> a[i];
    ll now = 0;
    loop(i,1,n+1){
        b[i] = cal(a[i-1], a[i]);
        now += b[i];
//        cout << now << '\n';
    }
    for(int i = n; i >= 1; i--){
        a[i] = a[i] - a[i-1];
    }
//    loop(i,0,n+1){
//        cout << a[i] << ' ';
//    } cout << '\n';
    loop(queries,0,q){
        int l, r; ll val;
        cin >> l >> r >> val;
        ll nxt_a = a[l] + val;
        ll nxt_b = cal(nxt_a);
        now -= b[l];
        b[l] = nxt_b;
        now += b[l];
        a[l] = nxt_a;

        if(r == n){
            cout << now << '\n';
            continue;
        }
        nxt_a = a[r+1] - val;
        nxt_b = cal(nxt_a);
        now -= b[r+1];
        b[r+1] = nxt_b;
        now += b[r+1];
        a[r+1] = nxt_a;
        cout << now << '\n';
    }
}

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