oj.uz

Submission #238664

# Submission time Handle Problem Language Result Execution time Memory
238664 2020-06-12T09:34:53 Z ganghe74 Salesman (IOI09_salesman) C++17
100 / 100
 520 ms 17888 KB 
#include <bits/stdc++.h>
using namespace std;

int n, u, d, s, t, p, m;
vector<tuple<int,int,int>> a;
vector<int> tu(1100000), td(1100000);

void update(vector<int> &t, int p, int v) {
    for (t[p += 500005]=v; p > 1; p >>= 1) t[p>>1] = max(t[p], t[p^1]);
}

int query(const vector<int> &t, int l, int r) {
    int ret = INT32_MIN;
    for (l+=500005,r+=500006; l<r; l>>=1,r>>=1) {
        if (l&1) ret = max(ret, t[l++]);
        if (r&1) ret = max(ret, t[--r]);
    }
    return ret;
}

int f(int x) {
    return max(query(td, 0, x)-d*x, query(tu, x, 500004)+u*x);
}

void up(int p, int di) {
    update(tu, p, max(di-u*p, query(tu, p, p)));
    update(td, p, max(di+d*p, query(td, p, p)));
}

int main() {
    scanf("%d%d%d%d", &n, &u, &d, &s);
    for (int i=0;i<n;++i) {
       scanf("%d%d%d", &t, &p, &m);
       a.push_back({t, p, m});
    }
    sort(a.begin(), a.end());

    for (int i=0;i<500005;++i) {
        update(tu, i, -2e9);
        update(td, i, -2e9);
    }
    up(s, 0);

    for (int i=0;i<n;++i) {
        if (i+1 < n && get<0>(a[i]) == get<0>(a[i+1])) {
            auto [t, p, m] = a[i];
            vector<tuple<int,int,int>> market;
            while (i < n && get<0>(a[i]) == t) market.push_back(a[i++]);
            i--;
            vector<int> l, r;
            for (auto [t, p, m] : market) {
                int y = f(p);
                l.push_back(y);
                r.push_back(y);
            }
            l[0] += get<2>(market[0]);
            r.back() += get<2>(market.back());
            for (int j=1;j<market.size();++j)
                l[j] = max(l[j], l[j-1] - d*(get<1>(market[j]) - get<1>(market[j-1]))) + get<2>(market[j]);
            for (int j=market.size()-2;j>=0;--j)
                r[j] = max(r[j], r[j+1] - u*(get<1>(market[j+1]) - get<1>(market[j]))) + get<2>(market[j]);
            for (int j=0;j<l.size();++j)
                up(get<1>(market[j]), max(l[j], r[j]));
        }
        else {
            auto [t, p, m] = a[i];
            up(p, f(p)+m);
        }
    }
    printf("%d", f(s));
}

Compilation message

salesman.cpp: In function 'int main()':
salesman.cpp:51:31: warning: unused variable 't' [-Wunused-variable]
             for (auto [t, p, m] : market) {
                               ^
salesman.cpp:51:31: warning: unused variable 'm' [-Wunused-variable]
salesman.cpp:58:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j=1;j<market.size();++j)
                          ~^~~~~~~~~~~~~~
salesman.cpp:62:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j=0;j<l.size();++j)
                          ~^~~~~~~~~
salesman.cpp:46:26: warning: unused variable 'p' [-Wunused-variable]
             auto [t, p, m] = a[i];
                          ^
salesman.cpp:46:26: warning: unused variable 'm' [-Wunused-variable]
salesman.cpp:66:26: warning: unused variable 't' [-Wunused-variable]
             auto [t, p, m] = a[i];
                          ^
salesman.cpp:31:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d%d", &n, &u, &d, &s);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
salesman.cpp:33:13: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
        scanf("%d%d%d", &t, &p, &m);
        ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 8960 KB Output is correct
2 Correct 35 ms 8960 KB Output is correct
3 Correct 35 ms 8960 KB Output is correct
4 Correct 36 ms 8960 KB Output is correct
5 Correct 38 ms 9216 KB Output is correct
6 Correct 53 ms 9792 KB Output is correct
7 Correct 87 ms 10364 KB Output is correct
8 Correct 132 ms 10992 KB Output is correct
9 Correct 173 ms 12656 KB Output is correct
10 Correct 281 ms 15716 KB Output is correct
11 Correct 330 ms 15720 KB Output is correct
12 Correct 402 ms 15716 KB Output is correct
13 Correct 408 ms 15720 KB Output is correct
14 Correct 499 ms 15716 KB Output is correct
15 Correct 429 ms 15720 KB Output is correct
16 Correct 520 ms 15720 KB Output is correct
17 Correct 36 ms 9088 KB Output is correct
18 Correct 35 ms 8960 KB Output is correct
19 Correct 36 ms 8960 KB Output is correct
20 Correct 37 ms 9088 KB Output is correct
21 Correct 39 ms 9216 KB Output is correct
22 Correct 39 ms 9216 KB Output is correct
23 Correct 40 ms 9216 KB Output is correct
24 Correct 39 ms 9216 KB Output is correct
25 Correct 122 ms 11128 KB Output is correct
26 Correct 217 ms 12652 KB Output is correct
27 Correct 327 ms 15840 KB Output is correct
28 Correct 365 ms 15716 KB Output is correct
29 Correct 450 ms 15716 KB Output is correct
30 Correct 462 ms 17888 KB Output is correct