diff --git a/Algorithms/Graph/NetworkFlow/MCMF.cpp b/Algorithms/Graph/NetworkFlow/MCMF.cpp new file mode 100644 index 0000000..d4ecc4d --- /dev/null +++ b/Algorithms/Graph/NetworkFlow/MCMF.cpp @@ -0,0 +1,73 @@ +#include +#include +inline int abs(int x) { return x < 0 ? -x : x; } +inline int min(int a, int b) { return a < b ? a : b; } +const int inf = 0x3f3f3f3f, maxn = 210, maxm = maxn * maxn; +int head[maxn], next[maxm], to[maxm], cap[maxm], cost[maxm], ecnt; +int dis[maxn], fa[maxn], que[maxm], cur[maxn]; +bool inq[maxn]; +inline void addEdge_impl_(int f, int t, int c, int v) +{ + next[ecnt] = head[f]; + head[f] = ecnt; + to[ecnt] = t; + cap[ecnt] = c; + cost[ecnt] = v; + ecnt++; +} +inline void addEdge(int f, int t, int c, int v) +{ + addEdge_impl_(f, t, c, v); + addEdge_impl_(t, f, 0, -v); +} +bool MCMF(int s, int e, int &c, int &v) +{ + memset(inq, 0, sizeof(inq)); + memset(dis, inf, sizeof(dis)); + int h = 0, t = 0, x; + cur[s] = inf; + inq[s] = true; + que[t++] = s; + dis[s] = 0; + for (; h != t; inq[que[h++]] = false) + for (int i = head[x = que[h]]; ~i; i = next[i]) + if (cap[i] > 0 && dis[to[i]] > dis[x] + cost[i]) + { + dis[to[i]] = dis[x] + cost[i]; + cur[to[i]] = min(cap[i], cur[x]); + fa[to[i]] = i; + if (!inq[to[i]]) inq[que[t++] = to[i]] = true; + } + if (dis[e] == inf) return false; + c += cur[e], v += cur[e] * dis[e]; + for (int i = e; i != s; i = to[fa[i] ^ 1]) + cap[fa[i]] -= cur[e], cap[fa[i] ^ 1] += cur[e]; + return true; +} +int M[maxn][2], mcnt, H[maxn][2], hcnt; +char buf[maxn]; +int main() +{ + int n, m; + while (~scanf("%d%d\n", &n, &m)) + { + if (n == 0 && m == 0) break; + memset(head, -1, sizeof(head)); + ecnt = mcnt = hcnt = 0; + for (int i = 0, j; i < n; i++) + for (j = 0, fgets(buf, 111, stdin); j < m; j++) + { + if (buf[j] == 'm') mcnt++, M[mcnt][0] = i, M[mcnt][1] = j; + if (buf[j] == 'H') hcnt++, H[hcnt][0] = i, H[hcnt][1] = j; + } + int S = 0, T = mcnt + hcnt + 2, C = 0, F = 0; + for (int i = 1; i <= mcnt; i++) addEdge(S, i, 1, 0); + for (int i = 1; i <= hcnt; i++) addEdge(mcnt + i, T, 1, 0); + for (int i = 1; i <= mcnt; i++) + for (int j = 1; j <= hcnt; j++) + addEdge(i, mcnt + j, 1, abs(M[i][0] - H[j][0]) + abs(M[i][1] - H[j][1])); + while (MCMF(S, T, F, C)); + printf("%d\n", C); + } + return 0; +} \ No newline at end of file