--- /dev/null
+/********************************************************************
+ ********************************************************************
+ **
+ ** libhungarian by Cyrill Stachniss, 2004
+ **
+ ** Added and adapted to libFirm by Christian Wuerdig, 2006
+ **
+ ** Solving the Minimum Assignment Problem using the
+ ** Hungarian Method.
+ **
+ ** ** This file may be freely copied and distributed! **
+ **
+ ** Parts of the used code was originally provided by the
+ ** "Stanford GraphGase", but I made changes to this code.
+ ** As asked by the copyright node of the "Stanford GraphGase",
+ ** I hereby proclaim that this file are *NOT* part of the
+ ** "Stanford GraphGase" distrubition!
+ **
+ ** This file is distributed in the hope that it will be useful,
+ ** but WITHOUT ANY WARRANTY; without even the implied
+ ** warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ ** PURPOSE.
+ **
+ ********************************************************************
+ ********************************************************************/
+
+/* $Id$ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "irtools.h"
+#include "xmalloc.h"
+#include "debug.h"
+#include "obst.h"
+
+#include "hungarian.h"
+
+#define INF (0x7FFFFFFF)
+
+struct _hungarian_problem_t {
+ int num_rows;
+ int num_cols;
+ int **cost;
+ int width;
+ int max_cost;
+ struct obstack obst;
+ DEBUG_ONLY(firm_dbg_module_t *dbg);
+};
+
+static INLINE void *get_init_mem(struct obstack *obst, long sz) {
+ void *p = obstack_alloc(obst, sz);
+ memset(p, 0, sz);
+ return p;
+}
+
+static void hungarian_dump_f(FILE *f, int **C, int rows, int cols, int width) {
+ int i, j;
+
+ fprintf(f , "\n");
+ for (i = 0; i < rows; i++) {
+ fprintf(f, " [");
+ for (j = 0; j < cols; j++) {
+ fprintf(f, "%*d", width, C[i][j]);
+ }
+ fprintf(f, "]\n");
+ }
+ fprintf(f, "\n");
+}
+
+void hungarian_print_costmatrix(hungarian_problem_t *p) {
+ hungarian_dump_f(stderr, p->cost, p->num_rows, p->num_cols, p->width);
+}
+
+/**
+ * Create the object and allocate memory for the data structures.
+ */
+hungarian_problem_t *hungarian_new(int rows, int cols, int width) {
+ int i;
+ int max_cost = 0;
+ hungarian_problem_t *p = xmalloc(sizeof(*p));
+
+ memset(p, 0, sizeof(p));
+
+ FIRM_DBG_REGISTER(p->dbg, "firm.hungarian");
+
+ /*
+ Is the number of cols not equal to number of rows ?
+ If yes, expand with 0 - cols / 0 - cols
+ */
+ rows = MAX(cols, rows);
+ cols = rows;
+
+ obstack_init(&p->obst);
+
+ p->num_rows = rows;
+ p->num_cols = cols;
+ p->width = width;
+ p->cost = (int **)get_init_mem(&p->obst, rows * sizeof(p->cost[0]));
+
+ /* allocate space for cost matrix */
+ for (i = 0; i < p->num_rows; i++)
+ p->cost[i] = (int *)get_init_mem(&p->obst, cols * sizeof(p->cost[0][0]));
+
+ return p;
+}
+
+/**
+ * Prepare the cost matrix.
+ */
+void hungarian_prepare_cost_matrix(hungarian_problem_t *p, int mode) {
+ int i, j;
+
+ if (mode == HUNGARIAN_MODE_MAXIMIZE_UTIL) {
+ for (i = 0; i < p->num_rows; i++) {
+ for (j = 0; j < p->num_cols; j++) {
+ p->cost[i][j] = p->max_cost - p->cost[i][j];
+ }
+ }
+ }
+ else if (mode == HUNGARIAN_MODE_MINIMIZE_COST) {
+ /* nothing to do */
+ }
+ else
+ fprintf(stderr, "Unknown mode. Mode was set to HUNGARIAN_MODE_MINIMIZE_COST.\n");
+}
+
+/**
+ * Set cost[left][right] to cost.
+ */
+void hungarian_add(hungarian_problem_t *p, int left, int right, int cost) {
+ assert(p->num_rows > left && "Invalid row selected.");
+ assert(p->num_cols > right && "Invalid column selected.");
+
+ p->cost[left][right] = cost;
+ p->max_cost = MAX(p->max_cost, cost);
+}
+
+/**
+ * Set cost[left][right] to 0.
+ */
+void hungarian_remv(hungarian_problem_t *p, int left, int right) {
+ assert(p->num_rows > left && "Invalid row selected.");
+ assert(p->num_cols > right && "Invalid column selected.");
+
+ p->cost[left][right] = 0;
+}
+
+/**
+ * Frees all allocated memory.
+ */
+void hungarian_free(hungarian_problem_t* p) {
+ obstack_free(&p->obst, NULL);
+ xfree(p);
+}
+
+/**
+ * Do the assignment.
+ */
+int hungarian_solve(hungarian_problem_t* p, int *assignment) {
+ int i, j, m, n, k, l, s, t, q, unmatched, cost;
+ int *col_mate;
+ int *row_mate;
+ int *parent_row;
+ int *unchosen_row;
+ int *row_dec;
+ int *col_inc;
+ int *slack;
+ int *slack_row;
+
+ cost = 0;
+ m = p->num_rows;
+ n = p->num_cols;
+
+ col_mate = xcalloc(p->num_rows, sizeof(col_mate[0]));
+ unchosen_row = xcalloc(p->num_rows, sizeof(unchosen_row[0]));
+ row_dec = xcalloc(p->num_rows, sizeof(row_dec[0]));
+ slack_row = xcalloc(p->num_rows, sizeof(slack_row[0]));
+
+ row_mate = xcalloc(p->num_cols, sizeof(row_mate[0]));
+ parent_row = xcalloc(p->num_cols, sizeof(parent_row[0]));
+ col_inc = xcalloc(p->num_cols, sizeof(col_inc[0]));
+ slack = xcalloc(p->num_cols, sizeof(slack[0]));
+
+#if 0
+ for (i = 0; i < p->num_rows; ++i) {
+ col_mate[i] = 0;
+ unchosen_row[i] = 0;
+ row_dec[i] = 0;
+ slack_row[i]=0;
+ }
+ for (j=0;j<p->num_cols;j++) {
+ row_mate[j]=0;
+ parent_row[j] = 0;
+ col_inc[j]=0;
+ slack[j]=0;
+ }
+#endif
+
+ memset(assignment, -1, m * sizeof(assignment[0]));
+
+ /* Begin subtract column minima in order to start with lots of zeros 12 */
+ DBG((p->dbg, LEVEL_1, "Using heuristic\n"));
+
+ for (l = 0; l < n; ++l) {
+ s = p->cost[0][l];
+
+ for (k = 1; k < m; ++k) {
+ if (p->cost[k][l] < s)
+ s = p->cost[k][l];
+ }
+
+ cost += s;
+
+ if (s != 0) {
+ for (k = 0; k < m; ++k)
+ p->cost[k][l] -= s;
+ }
+ }
+ /* End subtract column minima in order to start with lots of zeros 12 */
+
+ /* Begin initial state 16 */
+ t = 0;
+ for (l = 0; l < n; ++l) {
+ row_mate[l] = -1;
+ parent_row[l] = -1;
+ col_inc[l] = 0;
+ slack[l] = INF;
+ }
+
+ for (k = 0; k < m; ++k) {
+ s = p->cost[k][0];
+
+ for (l = 1; l < n; ++l) {
+ if (p->cost[k][l] < s)
+ s = p->cost[k][l];
+ }
+
+ row_dec[k] = s;
+
+ for (l = 0; l < n; ++l) {
+ if (s == p->cost[k][l] && row_mate[l] < 0) {
+ col_mate[k] = l;
+ row_mate[l] = k;
+ DBG((p->dbg, LEVEL_1, "matching col %d == row %d\n", l, k));
+ goto row_done;
+ }
+ }
+
+ col_mate[k] = -1;
+ DBG((p->dbg, LEVEL_1, "node %d: unmatched row %d\n", t, k));
+ unchosen_row[t++] = k;
+row_done: ;
+ }
+ /* End initial state 16 */
+
+ /* Begin Hungarian algorithm 18 */
+ if (t == 0)
+ goto done;
+
+ unmatched = t;
+ while (1) {
+ DBG((p->dbg, LEVEL_1, "Matched %d rows.\n", m - t));
+ q = 0;
+
+ while (1) {
+ while (q < t) {
+ /* Begin explore node q of the forest 19 */
+ k = unchosen_row[q];
+ s = row_dec[k];
+
+ for (l = 0; l < n; ++l) {
+ if (slack[l]) {
+ int del = p->cost[k][l] - s + col_inc[l];
+
+ if (del < slack[l]) {
+ if (del == 0) {
+ if (row_mate[l] < 0)
+ goto breakthru;
+
+ slack[l] = 0;
+ parent_row[l] = k;
+ DBG((p->dbg, LEVEL_1, "node %d: row %d == col %d -- row %d\n", t, row_mate[l], l, k));
+ unchosen_row[t++] = row_mate[l];
+ }
+ else {
+ slack[l] = del;
+ slack_row[l] = k;
+ }
+ }
+ }
+ }
+ /* End explore node q of the forest 19 */
+ q++;
+ }
+
+ /* Begin introduce a new zero into the matrix 21 */
+ s = INF;
+ for (l = 0; l < n; ++l) {
+ if (slack[l] && slack[l] < s)
+ s = slack[l];
+ }
+
+ for (q = 0; q < t; ++q)
+ row_dec[unchosen_row[q]] += s;
+
+ for (l = 0; l < n; ++l) {
+ if (slack[l]) {
+ slack[l] -= s;
+ if (slack[l] == 0) {
+ /* Begin look at a new zero 22 */
+ k = slack_row[l];
+ DBG((p->dbg, LEVEL_1, "Decreasing uncovered elements by %d produces zero at [%d, %d]\n", s, k, l));
+ if (row_mate[l] < 0) {
+ for (j = l + 1; j < n; ++j) {
+ if (slack[j] == 0)
+ col_inc[j] += s;
+ }
+ goto breakthru;
+ }
+ else {
+ parent_row[l] = k;
+ DBG((p->dbg, LEVEL_1, "node %d: row %d == col %d -- row %d\n", t, row_mate[l], l, k));
+ unchosen_row[t++] = row_mate[l];
+ }
+ /* End look at a new zero 22 */
+ }
+ }
+ else {
+ col_inc[l] += s;
+ }
+ }
+ /* End introduce a new zero into the matrix 21 */
+ }
+breakthru:
+ /* Begin update the matching 20 */
+ DBG((p->dbg, LEVEL_1, "Breakthrough at node %d of %d.\n", q, t));
+ while (1) {
+ j = col_mate[k];
+ col_mate[k] = l;
+ row_mate[l] = k;
+
+ DBG((p->dbg, LEVEL_1, "rematching col %d == row %d\n", l, k));
+ if (j < 0)
+ break;
+
+ k = parent_row[j];
+ l = j;
+ }
+ /* End update the matching 20 */
+
+ if (--unmatched == 0)
+ goto done;
+
+ /* Begin get ready for another stage 17 */
+ t = 0;
+ for (l = 0; l < n; ++l) {
+ parent_row[l] = -1;
+ slack[l] = INF;
+ }
+
+ for (k = 0; k < m; ++k) {
+ if (col_mate[k] < 0) {
+ DBG((p->dbg, LEVEL_1, "node %d: unmatched row %d\n", t, k));
+ unchosen_row[t++] = k;
+ }
+ }
+ /* End get ready for another stage 17 */
+ }
+done:
+
+ /* Begin double check the solution 23 */
+ for (k = 0; k < m; ++k) {
+ for (l = 0; l < n; ++l) {
+ if (p->cost[k][l] < row_dec[k] - col_inc[l])
+ return -1;
+ }
+ }
+
+ for (k = 0; k < m; ++k) {
+ l = col_mate[k];
+ if (l < 0 || p->cost[k][l] != row_dec[k] - col_inc[l])
+ return -2;
+ }
+
+ for (k = l = 0; l < n; ++l) {
+ if (col_inc[l])
+ k++;
+ }
+
+ if (k > m)
+ return -3;
+ /* End double check the solution 23 */
+
+ /* End Hungarian algorithm 18 */
+
+ /* collect the assigned values */
+ for (i = 0; i < m; ++i) {
+ assignment[i] = col_mate[i];
+ }
+
+ for (k = 0; k < m; ++k) {
+ for (l = 0; l < n; ++l) {
+ p->cost[k][l] = p->cost[k][l] - row_dec[k] + col_inc[l];
+ }
+ }
+
+ for (i = 0; i < m; ++i)
+ cost += row_dec[i];
+
+ for (i = 0; i < n; ++i)
+ cost -= col_inc[i];
+
+ DBG((p->dbg, LEVEL_1, "Cost is %d\n", cost));
+
+ xfree(slack);
+ xfree(col_inc);
+ xfree(parent_row);
+ xfree(row_mate);
+ xfree(slack_row);
+ xfree(row_dec);
+ xfree(unchosen_row);
+ xfree(col_mate);
+
+ return 0;
+}
--- /dev/null
+/********************************************************************
+ ********************************************************************
+ **
+ ** libhungarian by Cyrill Stachniss, 2004
+ **
+ **
+ ** Solving the Minimum Assignment Problem using the
+ ** Hungarian Method.
+ **
+ ** ** This file may be freely copied and distributed! **
+ **
+ ** Parts of the used code was originally provided by the
+ ** "Stanford GraphGase", but I made changes to this code.
+ ** As asked by the copyright node of the "Stanford GraphGase",
+ ** I hereby proclaim that this file are *NOT* part of the
+ ** "Stanford GraphGase" distrubition!
+ **
+ ** This file is distributed in the hope that it will be useful,
+ ** but WITHOUT ANY WARRANTY; without even the implied
+ ** warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ ** PURPOSE.
+ **
+ ********************************************************************
+ ********************************************************************/
+
+#ifndef _HUNGARIAN_H_
+#define _HUNGARIAN_H_
+
+#define HUNGARIAN_MODE_MINIMIZE_COST 0
+#define HUNGARIAN_MODE_MAXIMIZE_UTIL 1
+
+typedef struct _hungarian_problem_t hungarian_problem_t;
+
+/**
+ * This method initialize the hungarian_problem structure and init
+ * the cost matrix (missing lines or columns are filled with 0).
+ *
+ * @param rows Number of rows in the given matrix
+ * @param cols Number of cols in the given matrix
+ * @param width Element width for matrix dumping
+ * @return The problem object.
+ */
+hungarian_problem_t *hungarian_new(int rows, int cols, int width);
+
+/**
+ * Adds an edge from left to right with some costs.
+ */
+void hungarian_add(hungarian_problem_t *p, int left, int right, int cost);
+
+/**
+* Removes the edge from left to right.
+*/
+void hungarian_remv(hungarian_problem_t *p, int left, int right);
+
+/**
+ * Prepares the cost matrix, dependend on the given mode.
+ *
+ * @param p The hungarian object
+ * @param mode HUNGARIAN_MODE_MAXIMIZE_UTIL or HUNGARIAN_MODE_MINIMIZE_COST (default)
+ */
+void hungarian_prepare_cost_matrix(hungarian_problem_t *p, int mode);
+
+/**
+ * Destroys the hungarian object.
+ */
+void hungarian_free(hungarian_problem_t *p);
+
+/**
+ * This method computes the optimal assignment.
+ * @param p The hungarian object
+ * @param assignment The final assignment
+ * @return Negative value if solution is invalid, 0 otherwise
+ */
+int hungarian_solve(hungarian_problem_t *p, int *assignment);
+
+/**
+ * Print the cost matrix.
+ * @param p The hungarian object
+ */
+void hungarian_print_costmatrix(hungarian_problem_t *p);
+
+#endif /* _HUNGARIAN_H_ */
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