Submission #960095

#	Time	Username	Problem	Language	Result	Execution time	Memory
960095		sheldon	Toll (BOI17_toll)	C++14	0 / 100	274 ms	157020 KiB

toll

#include <bits/stdc++.h>

using namespace std;
#define int long long
const int nax = 5e4 + 5;


int dp[nax][16][5][5];

void combine (int first[5][5], int second[5][5], int third[5][5]) {
    for (int i = 0; i < 5; ++i) {
        for (int j = 0; j < 5; ++j) {
            for (int k = 0; k < 5; ++k) {
                third[i][k] = min (third[i][k], first[i][j] + second[j][k]); 
            }
        }
    }
}

void solve() {
    int k, n, m, q;
    cin >> k >> n >> m >> q;
    memset (dp, 0x3f, sizeof (dp));
    for (int i = 0; i < m; ++i) {
        int a, b, t;
        cin >> a >> b >> t;
        int loca = a / k, locb =  b / k;
        dp[loca][0][a % k][b % k] = min (dp[loca][0][a % k][b % k], t);
    }
    for (int bit = 1; bit < 16; ++bit) {
        for (int i = (n - 1) / k; i >= 0; --i) {
            if (i + (1 << bit) > (n - 1) / k) continue;

            combine (dp[i][bit - 1], dp[i + (1 << (bit - 1))][bit - 1], dp[i][bit]);
        }
    }

    while (q--) {
        int a, b;
        cin >> a >> b;
        int dist = b / k - a / k;
        int loca = a % k, locb = b % k;
        int at[5];
        memset (at, 0x3f, sizeof (at));
        bool found = 0;
        int node = a / k;
        for (int bit = 0; bit < 15; ++bit) {
            int new_dp[5];
            memset (new_dp, 0x3f, sizeof (new_dp));
            if (dist & (1 << bit)) {
                if (!found) {
                    for (int i = 0; i < k; ++i) {
                        at[i] = dp[a / k][bit][loca][i];
                    }
                    found = 1;
                } else {
                    for (int i = 0; i < k; ++i) {
                        for (int j = 0; j < k; ++j) {
                            new_dp[i] = min (new_dp[i], at[j] + dp[node][bit][j][i]);
                        }
                    }
                    for (int i = 0; i < k; ++i) {
                        at[i] = new_dp[i];
                    }
                }
                node += (1 << bit);
            }
        }
        cout << (at[locb] >= 1e9 ? -1 : at[locb]) << '\n';
    }
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    solve();
}

Compilation message (stderr)

toll.cpp: In function 'void solve()':
toll.cpp:27:27: warning: unused variable 'locb' [-Wunused-variable]
   27 |         int loca = a / k, locb =  b / k;
      |                           ^~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44