Submission #764644

#	Time	Username	Problem	Language	Result	Execution time	Memory
764644		raysh07	Swapping Cities (APIO20_swap)	C++17	37 / 100	2082 ms	7268 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
 
struct edge{
    int u, v, w;
};

int n, m;
const int maxn = 1e5 + 69;
vector <edge> e;
int root[maxn], deg[maxn], edg[maxn];

int find(int x){
    if (x == root[x]) return x;
    return root[x] = find(root[x]);
}

void unite(int x, int y){
    x = find(x); y = find(y);
    if (x == y) {
        edg[x]++;
        return;
    }
    root[y] = x;
    edg[x] += edg[y];
}
 
void init(int N, int M, vector<int> U, vector<int> V, vector<int> W) {
    n = N;
    m = M;
    e.resize(m);
    for (int i = 0; i < m; i++) {
        e[i].u = U[i];
        e[i].v = V[i];
        e[i].w = W[i];
    }
}
 
int getMinimumFuelCapacity(int x, int y) {
    int l = 0, r = 1e9 + 1;
    while (l != r){
        int mid = (l + r)/2;
        for (int i = 0; i < n; i++){
            root[i] = i;
            edg[i] = 0;
            deg[i] = 0;
        }
        
        for (int i = 0; i < m; i++){
            if (e[i].w > mid) continue;
            deg[e[i].u]++;
            deg[e[i].v]++;
            unite(e[i].u, e[i].v);
        }
        
        bool found = false;
        if (find(x) != find(y)) {
            l = mid + 1;
            continue;
        }
        
        if (edg[find(x)]) {
            found = true;
        }
        
        for (int i = 0; i < n; i++){
            if (find(i) == find(x) && deg[i] >= 3) //can turn here 
            found = true;
        }
        
        if (found) r = mid;
        else l = mid + 1;
    }
    if (l > 1e9) return -1;
    return l;
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 7
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27