|
| 1 | +/* |
| 2 | + |
| 3 | + Name: Mehul Chaturvedi |
| 4 | + IIT-Guwahati |
| 5 | + |
| 6 | +*/ |
| 7 | +/* |
| 8 | +An island is a small piece of land surrounded by water . A group of islands is said to be connected if we can reach from any given island to any other island in the same group . Given N islands (numbered from 1 to N) and two lists of size M (u and v) denoting island u[i] is connected to island v[i] and vice versa . Can you count the number of connected groups of islands. |
| 9 | +Constraints : |
| 10 | +1<=N<=100 |
| 11 | +1<=M<=(N*(N-1))/2 |
| 12 | +1<=u[i],v[i]<=N |
| 13 | +Input Format : |
| 14 | +Line 1 : Two integers N and M |
| 15 | +Line 2 : List u of size of M |
| 16 | +Line 3 : List v of size of M |
| 17 | +Output Return Format : |
| 18 | +The count the number of connected groups of islands |
| 19 | +Sample Input : |
| 20 | +2 1 |
| 21 | +1 |
| 22 | +2 |
| 23 | +Sample Output : |
| 24 | +1 |
| 25 | +*/ |
| 26 | + |
| 27 | +#include <bits/stdc++.h> |
| 28 | + |
| 29 | +using namespace std; |
| 30 | + |
| 31 | +void DFS(int** arr, int* visited, int n, int sv){ |
| 32 | + |
| 33 | + visited[sv] = 1; |
| 34 | + |
| 35 | + for (int i = 0; i < n; ++i) |
| 36 | + { |
| 37 | + if (i==sv) |
| 38 | + { |
| 39 | + continue; |
| 40 | + } |
| 41 | + if (arr[sv][i] == 1 && visited[i] == 0) |
| 42 | + { |
| 43 | + DFS(arr, visited, n, i); |
| 44 | + } |
| 45 | + } |
| 46 | + |
| 47 | + return; |
| 48 | +} |
| 49 | + |
| 50 | +int solve(int n,int m,vector<int>u,vector<int>v) |
| 51 | +{ |
| 52 | + int** arr = new int*[n]; |
| 53 | + for (int i = 0; i < n; ++i) |
| 54 | + { |
| 55 | + arr[i] = new int[n]; |
| 56 | + for (int j = 0; j < n; ++j) |
| 57 | + { |
| 58 | + arr[i][j] = 0; |
| 59 | + } |
| 60 | + } |
| 61 | + |
| 62 | + |
| 63 | + |
| 64 | + for (int i = 0; i < m; ++i) |
| 65 | + { |
| 66 | + arr[u[i]-1][v[i]-1] = 1; |
| 67 | + arr[v[i]-1][u[i]-1] = 1; |
| 68 | + } |
| 69 | + |
| 70 | + // for (int i = 0; i < n; ++i) |
| 71 | + // { |
| 72 | + // for (int j = 0; j < n; ++j) |
| 73 | + // { |
| 74 | + // cout<<i<<" "<<j<<" "<<arr[i][j]<<endl; |
| 75 | + // } |
| 76 | + // } |
| 77 | + // cout << '\n'; |
| 78 | + |
| 79 | + int* visited = new int[n]; |
| 80 | + |
| 81 | + for (int i = 0; i < n; ++i) |
| 82 | + { |
| 83 | + visited[i] = 0; |
| 84 | + } |
| 85 | + |
| 86 | + int count = 0; |
| 87 | + for (int i = 0; i < n; ++i) |
| 88 | + { |
| 89 | + if (visited[i]==0) |
| 90 | + { |
| 91 | + count++; |
| 92 | + DFS(arr, visited, n, i); |
| 93 | + } |
| 94 | + } |
| 95 | + |
| 96 | + return count; |
| 97 | +} |
| 98 | + |
| 99 | +int main( int argc , char ** argv ) |
| 100 | +{ |
| 101 | + ios_base::sync_with_stdio(false) ; |
| 102 | + cin.tie(NULL) ; |
| 103 | + |
| 104 | + int n,m; |
| 105 | + vector<int>u,v; |
| 106 | + cin>>n>>m; |
| 107 | + for(int i=0;i<m;i++) |
| 108 | + { |
| 109 | + int x; |
| 110 | + cin>>x; |
| 111 | + u.push_back(x); |
| 112 | + } |
| 113 | + for(int i=0;i<m;i++) |
| 114 | + { |
| 115 | + int x; |
| 116 | + cin>>x; |
| 117 | + v.push_back(x); |
| 118 | + } |
| 119 | + cout<<solve(n,m,u,v)<<endl; |
| 120 | + |
| 121 | +} |
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