HDU 1598 find the most comfortable road

Greedy + and query set

Fighting ~~~~~!!

1 # include <iostream> 2 # include <algorithm> 3 # include <cmath> 4 # include <cstdio> 5 using namespace STD; 6 # define maxn 300 7 # define INF 0x3fffffff 8 int par [maxn]; 9 int n, m; 10 11 struct node12 {13 int X; 14 int y; 15 int W; 16}; 17 node E [maxn * maxn/2]; 18 int CMP (const node & A, const node & B) 19 {20 return. W <B. w; 21} 22 void Init () 23 {24 for (INT I = 1; I <= N; I ++) 25 par [I] = I; 26} 27 int find (in T x) 28 {29 int T, R, K; 30 k = x; 31 While (X! = Par [x]) 32 x = par [X]; 33 while (K! = X) // tanta34 {35 t = par [k]; 36 par [k] = x; 37 k = T; 38} 39 return X; 40} 41 void merge (int x, int y) 42 {43 int A = find (x); 44 int B = find (y); 45 if (! = B) 46 {47 par [a] = B; 48} 49} 50 void Kruskal () 51 {52 int Q, St, en, mindis, I, j; 53 While (CIN> N> m) 54 {55 for (INT I = 0; I <m; I ++) 56 CIN> E [I]. x> E [I]. y> E [I]. w; 57 sort (E, E + M, CMP); 58 CIN> q; 59 While (Q --) 60 {61 CIN> st> en; 62 mindis = inf; 63 for (I = 0; I <m; I ++) // meijuzuixiao64 {65 Init (); 66 for (j = I; j <m; j ++) // zhaozuidabian67 {68 Merge (E [J]. x, E [J]. y); 69 If (find (ST) = find (En) // start point end point connection 70 {71 Mindis = min (mindis, E [J]. w-e [I]. w); 72 break; 73} 74} 75 if (j = m) break; // J = m continue enumeration and 76} 77 If (mindis! = Inf) cout <mindis <Endl; 78 else cout <"-1" <Endl; 79} 80} 81} 82 int main () 83 {84 freopen ("input.txt", "r", stdin); 85 Kruskal (); 86 return 0; 87}

 

HDU 1598 find the most comfortable road