#include "sabotaz.h" #include "message.h" #include<bits/stdc++.h> #define ST first #define ND second using namespace std; using LL = long long; using PII = pair<int, int>; const int N = 2e5; int n, m; int repr[N]; int rankk[N]; int find(int u){ return repr[u] == u ? u : repr[u] = find(repr[u]); } void merge(int u, int v){ u = find(u); v = find(v); if(rankk[u] == rankk[v]) rankk[v]++; if(rankk[u] > rankk[v]) swap(u, v); repr[u] = v; } struct edge { int v; int i; edge(int v, int i):v(v),i(i){} }; vector<edge> g[N]; int gsize; void addedge(int u, int v){ g[u].emplace_back(v, gsize); g[v].emplace_back(u, gsize); gsize++; } int depth[N]; int dfs(int u, int d, int i){ // cout << "dfs(" << u << ", " << d << ", " << i << ")" << endl; depth[u] = d; int lowdepth = d + 1; for(edge e : g[u]) if(e.i != i){ if(depth[e.v] != -1){ merge(u, e.v); //cout << "merge" << u << e.v << " (-)" << endl; //cout << "lowdepth " << lowdepth << " depth " << depth[e.v]; lowdepth = min(lowdepth, depth[e.v]); } else { int s = dfs(e.v, d+1, e.i); if(s <= depth[u]){ // cout << "merge" << u << e.v << " (+)" << endl; merge(u, e.v); lowdepth = min(lowdepth, s); } lowdepth = min(lowdepth, s); } } //cout << "low(" << u << ") = " << lowdepth << endl; return lowdepth; } vector<PII> edges; vector<vector<int>> classes; int bridges; void minimizegraph(){ gsize = 0; fill_n(g, n, vector<edge>()); for(PII p : edges){ addedge(p.ST, p.ND); } fill_n(depth, n, -1); fill_n(rankk, n, 0); iota(repr, repr + n, 0); for(int u = 0; u < n; u++) if(depth[u] == -1){ dfs(u, 0, -1); } vector<PII> newedges; bridges = 0; for(int u = 0; u < n; u++){ for(edge e : g[u]){ if(e.v < u && find(e.v) != find(u)){ bridges++; newedges.push_back(PII(e.v, u)); } } } classes.resize(n); fill_n(classes.begin(), n, vector<int>()); for(int u = 0; u < n; u++){ classes[find(u)].push_back(u); } for(int i = 0; i < n; i++){ if(classes[i].size() > 1){ for(int j = 0; j < (int) classes[i].size(); j++){ //cout << classes[i][j] << " "; newedges.emplace_back(classes[i][j], classes[i][(j+1)%classes[i].size()]); } //cout << endl; } } edges = newedges; } void printgraph(){ //for(PII e : edges) printf("%d %d\n", e.ST, e.ND); //printf("=========\n"); //printf("%d\n", bridges); } const int EDGES_IN_MESSAGE = 1000; int main(){ int numberOfNodes = NumberOfNodes(); int myNodeId = MyNodeId(); n = NumberOfIsles(); m = NumberOfBridges(); int begin = (LL) myNodeId * m / numberOfNodes; int end = (LL) (myNodeId + 1) * m / numberOfNodes; for(int i = begin; i < end; i++){ int a = BridgeEndA(i); int b = BridgeEndB(i); edges.emplace_back(a, b); } printgraph(); minimizegraph(); printgraph(); for(int i = 0; (1<<i) <= numberOfNodes - 1; i++){ int yourNodeId = myNodeId ^ (1<<i); if(yourNodeId >= numberOfNodes) continue; if(myNodeId & (1<<i)){ PutInt(yourNodeId, edges.size()); Send(yourNodeId); for(int j = 0; j < (edges.size() + EDGES_IN_MESSAGE - 1) / EDGES_IN_MESSAGE; j++){ for(int k = j * EDGES_IN_MESSAGE; k < min((j+1) * EDGES_IN_MESSAGE, (int)edges.size()); k++){ //cout << "k = " << k << " e = " << edges[k].ST << " " << edges[k].ND << endl; PutInt(yourNodeId, edges[k].ST); PutInt(yourNodeId, edges[k].ND); } Send(yourNodeId); } return 0; } else { Receive(yourNodeId); int size = GetInt(yourNodeId); for(int j = 0; j < (size + EDGES_IN_MESSAGE - 1) / EDGES_IN_MESSAGE; j++){ Receive(yourNodeId); for(int k = j * EDGES_IN_MESSAGE; k < min((j+1) * EDGES_IN_MESSAGE, size); k++){ int a = GetInt(yourNodeId); int b = GetInt(yourNodeId); edges.emplace_back(a, b); } } printgraph(); minimizegraph(); printgraph(); } } printf("%d\n", bridges); }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 | #include "sabotaz.h" #include "message.h" #include<bits/stdc++.h> #define ST first #define ND second using namespace std; using LL = long long; using PII = pair<int, int>; const int N = 2e5; int n, m; int repr[N]; int rankk[N]; int find(int u){ return repr[u] == u ? u : repr[u] = find(repr[u]); } void merge(int u, int v){ u = find(u); v = find(v); if(rankk[u] == rankk[v]) rankk[v]++; if(rankk[u] > rankk[v]) swap(u, v); repr[u] = v; } struct edge { int v; int i; edge(int v, int i):v(v),i(i){} }; vector<edge> g[N]; int gsize; void addedge(int u, int v){ g[u].emplace_back(v, gsize); g[v].emplace_back(u, gsize); gsize++; } int depth[N]; int dfs(int u, int d, int i){ // cout << "dfs(" << u << ", " << d << ", " << i << ")" << endl; depth[u] = d; int lowdepth = d + 1; for(edge e : g[u]) if(e.i != i){ if(depth[e.v] != -1){ merge(u, e.v); //cout << "merge" << u << e.v << " (-)" << endl; //cout << "lowdepth " << lowdepth << " depth " << depth[e.v]; lowdepth = min(lowdepth, depth[e.v]); } else { int s = dfs(e.v, d+1, e.i); if(s <= depth[u]){ // cout << "merge" << u << e.v << " (+)" << endl; merge(u, e.v); lowdepth = min(lowdepth, s); } lowdepth = min(lowdepth, s); } } //cout << "low(" << u << ") = " << lowdepth << endl; return lowdepth; } vector<PII> edges; vector<vector<int>> classes; int bridges; void minimizegraph(){ gsize = 0; fill_n(g, n, vector<edge>()); for(PII p : edges){ addedge(p.ST, p.ND); } fill_n(depth, n, -1); fill_n(rankk, n, 0); iota(repr, repr + n, 0); for(int u = 0; u < n; u++) if(depth[u] == -1){ dfs(u, 0, -1); } vector<PII> newedges; bridges = 0; for(int u = 0; u < n; u++){ for(edge e : g[u]){ if(e.v < u && find(e.v) != find(u)){ bridges++; newedges.push_back(PII(e.v, u)); } } } classes.resize(n); fill_n(classes.begin(), n, vector<int>()); for(int u = 0; u < n; u++){ classes[find(u)].push_back(u); } for(int i = 0; i < n; i++){ if(classes[i].size() > 1){ for(int j = 0; j < (int) classes[i].size(); j++){ //cout << classes[i][j] << " "; newedges.emplace_back(classes[i][j], classes[i][(j+1)%classes[i].size()]); } //cout << endl; } } edges = newedges; } void printgraph(){ //for(PII e : edges) printf("%d %d\n", e.ST, e.ND); //printf("=========\n"); //printf("%d\n", bridges); } const int EDGES_IN_MESSAGE = 1000; int main(){ int numberOfNodes = NumberOfNodes(); int myNodeId = MyNodeId(); n = NumberOfIsles(); m = NumberOfBridges(); int begin = (LL) myNodeId * m / numberOfNodes; int end = (LL) (myNodeId + 1) * m / numberOfNodes; for(int i = begin; i < end; i++){ int a = BridgeEndA(i); int b = BridgeEndB(i); edges.emplace_back(a, b); } printgraph(); minimizegraph(); printgraph(); for(int i = 0; (1<<i) <= numberOfNodes - 1; i++){ int yourNodeId = myNodeId ^ (1<<i); if(yourNodeId >= numberOfNodes) continue; if(myNodeId & (1<<i)){ PutInt(yourNodeId, edges.size()); Send(yourNodeId); for(int j = 0; j < (edges.size() + EDGES_IN_MESSAGE - 1) / EDGES_IN_MESSAGE; j++){ for(int k = j * EDGES_IN_MESSAGE; k < min((j+1) * EDGES_IN_MESSAGE, (int)edges.size()); k++){ //cout << "k = " << k << " e = " << edges[k].ST << " " << edges[k].ND << endl; PutInt(yourNodeId, edges[k].ST); PutInt(yourNodeId, edges[k].ND); } Send(yourNodeId); } return 0; } else { Receive(yourNodeId); int size = GetInt(yourNodeId); for(int j = 0; j < (size + EDGES_IN_MESSAGE - 1) / EDGES_IN_MESSAGE; j++){ Receive(yourNodeId); for(int k = j * EDGES_IN_MESSAGE; k < min((j+1) * EDGES_IN_MESSAGE, size); k++){ int a = GetInt(yourNodeId); int b = GetInt(yourNodeId); edges.emplace_back(a, b); } } printgraph(); minimizegraph(); printgraph(); } } printf("%d\n", bridges); } |