Submission #138868

#	Time	Username	Problem	Language	Result	Execution time	Memory
138868		RiscadoA	Roller Coaster Railroad (IOI16_railroad)	C++14	0 / 100	75 ms	3604 KiB

railroad

#include "railroad.h"

const int INF = 1000000001;
const int MAX_N = 16;
const int MAX_MASK = 0xFFFF;
int N, S[MAX_N], T[MAX_N];

long long dp[MAX_N + 1][MAX_MASK];

inline long long max(long long a, long long b)
{
        return a > b ? a : b;
}

inline long long min(long long a, long long b)
{
        return a < b ? a : b;
}

long long calc(int next, int mask)
{
        if (dp[next][mask] == -1) {
                int s;
                if (next == MAX_N)
                        s = INF;
                else
                        s = S[next];

                long long v = 0x7FFFFFFFFFFFFFFF;
                for (int i = 0, j = 1; i < N; ++i, j <<= 1)
                        if (mask & j)
                                v = min(v, max(0, T[i] - s) + calc(i, mask & (~j)));
                dp[next][mask] = v;
        }

        return dp[next][mask];
}

long long plan_roller_coaster(std::vector<int> s, std::vector<int> t)
{
        N = (int)s.size();
        if (N > 16)
                return -1;
        for (int i = 0; i < N; ++i) {
                S[i] = s[i];
                T[i] = t[i];
        }

        for (int i = 0; i <= N; ++i) {
                dp[i][0] = 0;
                for (int m = 1; m < MAX_MASK; ++m)
                        dp[i][m] = -1;
        }

        return calc(MAX_N, 0xFFFF >> (16 - N));
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 23
• Subtask 3: 0 / 30
• Subtask 4: 0 / 36