vector< vector > adjlist; vector pairs; //for every node, stores the matching node on the other side or -1 vector visited; bool dfs(int i) { if (visited[i]) return false; visited[i] = true; for (vector::iterator vit = adjlist[i].begin(); vit != adjlist[i].end(); vit++) { if (pairs[*vit] < 0 || dfs(pairs[*vit])) { pairs[*vit] = i; pairs[i] = *vit; return true; } } return false; } int kuhn(int n, int m) { // n = nodes on left side (numbered 0..n-1), m = nodes on the right side pairs.assign(n + m, -1); int ans = 0; for (int i = 0; i < n; i++) { visited.assign(n + m, false); ans += dfs(i); } return ans; //size of the MCBM }