Submission #527069

#	Time	Username	Problem	Language	Result	Execution time	Memory
527069		Lobo	Bridges (APIO19_bridges)	C++17	16 / 100	657 ms	5416 KiB

bridges

#include<bits/stdc++.h>
using namespace std;

const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()

#define maxn 55000

int n, m, q, tr[4*maxn], u[maxn], v[maxn], w[maxn];

void att(int no, int l, int r, int pos, int val) {
    if(l > pos || r < pos) return;
    else if(l == r) {
        tr[no] = val;
    }
    else {
        int f1 = 2*no;
        int f2 = 2*no+1;
        int mid = (l+r)/2;

        att(f1,l,mid,pos,val);
        att(f2,mid+1,r,pos,val);
        tr[no] = min(tr[f1],tr[f2]);
    }
}

int qrr(int no, int l, int r, int L, int R) {
    if(l > R || r < L) return inf;
    else if(l >= L && r <= R) {
        return tr[no];
    }
    else {
        int f1 = 2*no;
        int f2 = 2*no+1;
        int mid = (l+r)/2;

        return min(qrr(f1,l,mid,L,R),qrr(f2,mid+1,r,L,R));
    }
}


void solve() {
    cin >> n >> m;

    for(int i = 1; i <= m; i++) {
        cin >> u[i] >> v[i] >> w[i];
    }

    cin >> q;


    for(int i = 1; i <= n; i++) {
        att(1,1,n-1,i,w[i]);
    }

    for(int i = 1; i <= q; i++) {
        int op; cin >> op;
        if(op == 1) {
            int id, val; cin >> id >> val;
            att(1,1,n-1,id,val);
        }
        else {
            int w1, v; cin >> v >> w1;

            int ans = 0;
            //busca binaria na seg
            int l = 1;
            int r = v-1;
            int ans1 = 0;
            while(l <= r) {
                int mid = (l+r)/2;
                // cout << v << " " << w1 << " " << mid << " " << qrr(1,1,n-1,1,mid) << endl;
                if(qrr(1,1,n-1,mid,v-1) >= w1) {
                    ans1 = v-mid;
                    r = mid-1;
                }
                else 
                    l = mid+1;
            }

            l = v;
            r = n-1;
            int ans2 = 0;
            while(l <= r) {
                int mid = (l+r)/2;
                // cout << v << " " << w1 << " " << mid << " " << qrr(1,1,n-1,v,mid) << endl;
                if(qrr(1,1,n-1,v,mid) >= w1) {
                    ans2 = mid-v+1;
                    l = mid+1;
                }
                else 
                    r = mid-1;
            }

            cout << ans1+ans2+1 << endl;
            // cout << ans1 << " " << ans2 << endl;
        }
    }


}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0);

    // freopen("in.in", "r", stdin);
    //freopen("out.out", "w", stdout);

    int tt = 1;
    // cin >> tt;
    while(tt--) solve();

}

Compilation message (stderr)

bridges.cpp: In function 'void solve()':
bridges.cpp:73:17: warning: unused variable 'ans' [-Wunused-variable]
   73 |             int ans = 0;
      |                 ^~~

• Subtask 1: 0 / 13
• Subtask 2: 16 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27