Submission #99984

#	Time	Username	Problem	Language	Result	Execution time	Memory
99984		tqbfjotld	Roller Coaster Railroad (IOI16_railroad)	C++14	11 / 100	2062 ms	276448 KiB

railroad

#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> s_;
vector<int> t_;
long long mem[17][1000000];

long long recurse(int cur, int bitmask){
if (bitmask==0) return 0;
if (mem[cur][bitmask]!=-1) return mem[cur][bitmask];
int original = bitmask;
long long ans = 999999999999999;
for (int x = 0; ; x++){
    if (bitmask==0) break;
    if ((bitmask&(1<<x))!=0){
        ans = min(ans,recurse(x,original-(1<<x))+((t_[cur]>s_[x])?(t_[cur]-s_[x]):0));
        bitmask-=(1<<x);
    }
}
return mem[cur][bitmask] = ans;

}


long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
    int n = (int) s.size();
    if (n<=8){
        vector<int> v;
        for (int x = 0; x<n; x++){
            v.push_back(x);

        }
        long long ans = 999999999999999;
        long long curans = 0;
        for (int x = 1; x<n; x++){
            curans+=(t[x-1]>s[x])?(t[x-1]-s[x]):0;
        }
        ans = min(curans,ans);
        while (next_permutation(v.begin(),v.end())){
            long long curans = 0;
            for (int x = 1; x<n; x++){
                curans+=(t[v[x-1]]>s[v[x]])?(t[v[x-1]]-s[v[x]]):0;
            }
            ans = min(curans,ans);
        }
        return ans;
    }
    else{
        memset(mem,-1,sizeof(mem));
        for (int x = 0; x<n; x++){
            s_.push_back(s[x]);
            t_.push_back(t[x]);
        }
        long long ans = 999999999999999;
        for (int x = 0; x<n; x++){
            ans = min(ans,recurse(x,(1<<n)-1-(1<<x)));
        }
        return ans;
    }
    return 0;
}

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