#36938: (C++)自己測是沒問可是過來就變成segmentational fault :-(
p0966543710@gmail.com
(Nicole Yang)
學校
:
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編號 : 238960
來源 : [140.116.7.109]
最後登入時間 ：
2024-03-17 10:36:08
#include <iostream>
#include <vector>
#include <map>
using namespace std;
int find_top(vector<vector<int>> &F,int top[],int P){
int top_num = -1;
while(top_num==-1){
for(int i = 0; i < P;i++){
if(top[i]!=0){
if(F[i][1]==-1){
top[i] = 0;
top[F[i][0]] = 1;
break;
}
else if(F[i][1]!=-1){
top_num = i;
return top_num;
break;
}
}
}
}
return top_num;
}
int find_len1(vector<vector<int>> F, int P, int top, int parent, vector<int>& visited) {
int max_len = 0;
visited[top] = 1;
for (int i = 0; i < P; i++) {
if (F[top][i] != -1 && F[top][i] != parent && !visited[F[top][i]]) {
int len = find_len1(F, P, F[top][i], top, visited) + 1;
max_len = max(max_len, len);
}
}
visited[top] = 0;
return max_len;
}
int find_len2(vector<vector<int>> F, int P, int top, int parent, vector<int>& visited) {
int max1 = 0, max2 = 0, len1 = 0;
visited[top] = 1;
for (int i = 0; i < P; i++) {
if (F[top][i] != -1 && F[top][i] != parent && !visited[F[top][i]]) {
int len = find_len2(F, P, F[top][i], top, visited) + 1;
len1 = max(len1, len);
if (len1 >= max1) {
max2 = max1;
max1 = len1;
} else if (len1 > max2) {
max2 = len1;
}
}
}
visited[top] = 0;
return max2;
}
int main(){
int P,N,n;
cin >> P;
vector<vector<int>> F(P, vector<int>(P,-1));
int T[P];
while(cin>>N){
cin >> n;
T[n] = 0;
for(int i = 0; i < P; i++){
if(F[N][i]==-1){
F[N][i] = n;
break;
}
}
}
int a = find_top(F,T,P);
vector<int> visited(P, 0);
int max1 = find_len1(F, P, a, -1, visited);
int max2 = find_len2(F, P, a, -1, visited);
int sum = max1 + max2;
cout << sum << endl;
return 0;
}
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