Maximum vertex independence set
Analysis: Maximum vertex Independent Set
Code:
1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <vector> 5 using namespace std; 6 7 const int maxn = 505; 8 9 int n;10 int Link[maxn];11 int vis[maxn];12 vector<int> G[maxn];13 bool Find(int u) {14 for(int i = 0; i < G[u].size(); i++) {15 int v = G[u][i];16 if(!vis[v]) {17 vis[v] = 1;18 if(Link[v] == -1 || Find(Link[v])) {19 Link[v] = u;20 return true;21 }22 }23 }24 return false;25 }26 27 int solve() {28 memset(Link, -1, sizeof(Link));29 int ans = 0;30 for(int i = 0; i < n; i++) {31 if(G[i].size()) {32 memset(vis, 0, sizeof(vis));33 if(Find(i)) ans ++;34 }35 }36 return ans;37 }38 39 int main() {40 int a, num, b;41 while(EOF != scanf("%d",&n)) {42 for(int i = 0; i < n; i++) {43 G[i].clear();44 }45 for(int i = 0; i < n; i++) {46 scanf("%d: (%d)", &a, &num);47 for(int j = 0; j < num; j++) {48 scanf("%d",&b);49 G[a].push_back(b);50 }51 }52 printf("%d\n", ( 2 * n - solve() ) / 2 );53 }54 return 0;55 }
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Poj 1466 girls and boys [maximum vertex independence set]