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Submission #56325

# Submission time Handle Problem Language Result Execution time Memory
56325 2018-07-11T05:10:24 Z admin Pipes (CEOI15_pipes) C++14
100 / 100
 1434 ms 7928 KB 
#include <bits/stdc++.h>
using namespace std;
 
const int N = 100001, H = 17;
 
int n, m, p[N], P[N], c[N], d[N], s[N];
vector<int> e[N];
 
int f(int x){ return p[x] = (x == p[x] ? x : f(p[x])); }
int F(int x){ return P[x] = (x == P[x] ? x : F(P[x])); }
 
void g(int x, int y, int z){
    for(int i : e[x]) if(i != y) g(i, x, z + 1);
    if(s[x] != y && x != f(x)) P[s[x]] = (P[x] == x ? s[x] : x);
    d[x] = z; s[x] = y;
}
 
int main(){
    scanf("%d%d", &n, &m);
    iota(p, p + n + 1, 0);
    iota(P, P + n + 1, 0);
    iota(s, s + n + 1, 0);
    fill(c + 1, c + n + 1, 1);
    for(int x, y; m--; ){
        scanf("%d%d", &x, &y);
        if(f(x) != f(y)){
            if(c[f(x)] < c[f(y)]) swap(x, y);
            g(y, x, d[x] + 1); P[y] = y;
            e[x].push_back(y); e[y].push_back(x);
            c[f(x)] += c[f(y)]; p[f(y)] = f(x);
        }
        else{
            x = F(x); y = F(y);
            while(x != y){
                if(d[x] > d[y]){ P[x] = F(P[s[x]]); x = F(x); }
                else{ P[y] = F(P[s[y]]); y = F(y); }
            }
        }
    }
    for(int i = 1; i <= n; i++) if(P[i] == i && s[i] != i) printf("%d %d\n", i, s[i]);
}

Compilation message

pipes.cpp: In function 'int main()':
pipes.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~
pipes.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &x, &y);
         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2688 KB Output is correct
2 Correct 3 ms 2688 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 2944 KB Output is correct
2 Correct 7 ms 2944 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 112 ms 2816 KB Output is correct
2 Correct 113 ms 2900 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 194 ms 3132 KB Output is correct
2 Correct 230 ms 3180 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 317 ms 3840 KB Output is correct
2 Correct 284 ms 4216 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 453 ms 6288 KB Output is correct
2 Correct 431 ms 6264 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 707 ms 6824 KB Output is correct
2 Correct 717 ms 6776 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1042 ms 7732 KB Output is correct
2 Correct 991 ms 7928 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1247 ms 7680 KB Output is correct
2 Correct 1209 ms 7820 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1434 ms 7516 KB Output is correct
2 Correct 1368 ms 7852 KB Output is correct