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ANSCORE/modules/ANSMOT/ByteTrack/src/lapjv.cpp

339 lines
8.0 KiB
C++

#include "lapjv.h"
#include <cstddef>
#include <cstring>
#include <stdexcept>
#define LAPJV_CPP_NEW(x, t, n) if ((x = (t *)malloc(sizeof(t) * (n))) == 0) { return -1; }
#define LAPJV_CPP_FREE(x) if (x != 0) { free(x); x = 0; }
#define LAPJV_CPP_SWAP_INDICES(a, b) { int _temp_index = a; a = b; b = _temp_index; }
namespace
{
constexpr size_t LARGE = 1000000;
enum class fp_t {
FP_1 = 1,
FP_2 = 2,
FP_DYNAMIC = 3,
};
/** Column-reduction and reduction transfer for a dense cost matrix.
*/
int _ccrrt_dense(const size_t n, double *cost[],
int *free_rows, int *x, int *y, double *v)
{
int n_free_rows;
bool *unique;
for (size_t i = 0; i < n; i++) {
x[i] = -1;
v[i] = LARGE;
y[i] = 0;
}
for (size_t i = 0; i < n; i++) {
for (size_t j = 0; j < n; j++) {
const double c = cost[i][j];
if (c < v[j]) {
v[j] = c;
y[j] = i;
}
}
}
LAPJV_CPP_NEW(unique, bool, n);
memset(unique, true, n);
{
int j = n;
do {
j--;
const int i = y[j];
if (x[i] < 0) {
x[i] = j;
}
else {
unique[i] = false;
y[j] = -1;
}
} while (j > 0);
}
n_free_rows = 0;
for (size_t i = 0; i < n; i++) {
if (x[i] < 0) {
free_rows[n_free_rows++] = i;
}
else if (unique[i]) {
const int j = x[i];
double min = LARGE;
for (size_t j2 = 0; j2 < n; j2++) {
if (j2 == (size_t)j) {
continue;
}
const double c = cost[i][j2] - v[j2];
if (c < min) {
min = c;
}
}
v[j] -= min;
}
}
LAPJV_CPP_FREE(unique);
return n_free_rows;
}
/** Augmenting row reduction for a dense cost matrix.
*/
int _carr_dense(
const size_t n, double *cost[],
const size_t n_free_rows,
int *free_rows, int *x, int *y, double *v)
{
size_t current = 0;
int new_free_rows = 0;
size_t rr_cnt = 0;
while (current < n_free_rows) {
int i0;
int j1, j2;
double v1, v2, v1_new;
bool v1_lowers;
rr_cnt++;
const int free_i = free_rows[current++];
j1 = 0;
v1 = cost[free_i][0] - v[0];
j2 = -1;
v2 = LARGE;
for (size_t j = 1; j < n; j++) {
const double c = cost[free_i][j] - v[j];
if (c < v2) {
if (c >= v1) {
v2 = c;
j2 = j;
}
else {
v2 = v1;
v1 = c;
j2 = j1;
j1 = j;
}
}
}
i0 = y[j1];
v1_new = v[j1] - (v2 - v1);
v1_lowers = v1_new < v[j1];
if (rr_cnt < current * n) {
if (v1_lowers) {
v[j1] = v1_new;
}
else if (i0 >= 0 && j2 >= 0) {
j1 = j2;
i0 = y[j2];
}
if (i0 >= 0) {
if (v1_lowers) {
free_rows[--current] = i0;
}
else {
free_rows[new_free_rows++] = i0;
}
}
}
else {
if (i0 >= 0) {
free_rows[new_free_rows++] = i0;
}
}
x[free_i] = j1;
y[j1] = free_i;
}
return new_free_rows;
}
/** Find columns with minimum d[j] and put them on the SCAN list.
*/
size_t _find_dense(const size_t n, size_t lo, double *d, int *cols, int *y)
{
size_t hi = lo + 1;
double mind = d[cols[lo]];
for (size_t k = hi; k < n; k++) {
int j = cols[k];
if (d[j] <= mind) {
if (d[j] < mind) {
hi = lo;
mind = d[j];
}
cols[k] = cols[hi];
cols[hi++] = j;
}
}
return hi;
}
// Scan all columns in TODO starting from arbitrary column in SCAN
// and try to decrease d of the TODO columns using the SCAN column.
int _scan_dense(const size_t n, double *cost[],
size_t *plo, size_t*phi,
double *d, int *cols, int *pred,
int *y, double *v)
{
size_t lo = *plo;
size_t hi = *phi;
double h, cred_ij;
while (lo != hi) {
int j = cols[lo++];
const int i = y[j];
const double mind = d[j];
h = cost[i][j] - v[j] - mind;
// For all columns in TODO
for (size_t k = hi; k < n; k++) {
j = cols[k];
cred_ij = cost[i][j] - v[j] - h;
if (cred_ij < d[j]) {
d[j] = cred_ij;
pred[j] = i;
if (cred_ij == mind) {
if (y[j] < 0) {
return j;
}
cols[k] = cols[hi];
cols[hi++] = j;
}
}
}
}
*plo = lo;
*phi = hi;
return -1;
}
/** Single iteration of modified Dijkstra shortest path algorithm as explained in the JV paper.
*
* This is a dense matrix version.
*
* \return The closest free column index.
*/
int find_path_dense(
const size_t n, double *cost[],
const int start_i,
int *y, double *v,
int *pred)
{
size_t lo = 0, hi = 0;
int final_j = -1;
size_t n_ready = 0;
int *cols;
double *d;
LAPJV_CPP_NEW(cols, int, n);
LAPJV_CPP_NEW(d, double, n);
for (size_t i = 0; i < n; i++) {
cols[i] = i;
pred[i] = start_i;
d[i] = cost[start_i][i] - v[i];
}
while (final_j == -1) {
// No columns left on the SCAN list.
if (lo == hi) {
n_ready = lo;
hi = _find_dense(n, lo, d, cols, y);
for (size_t k = lo; k < hi; k++) {
const int j = cols[k];
if (y[j] < 0) {
final_j = j;
}
}
}
if (final_j == -1) {
final_j = _scan_dense(
n, cost, &lo, &hi, d, cols, pred, y, v);
}
}
{
const double mind = d[cols[lo]];
for (size_t k = 0; k < n_ready; k++) {
const int j = cols[k];
v[j] += d[j] - mind;
}
}
LAPJV_CPP_FREE(cols);
LAPJV_CPP_FREE(d);
return final_j;
}
/** Augment for a dense cost matrix.
*/
int _ca_dense(
const size_t n, double *cost[],
const size_t n_free_rows,
int *free_rows, int *x, int *y, double *v)
{
int *pred;
LAPJV_CPP_NEW(pred, int, n);
for (int *pfree_i = free_rows; pfree_i < free_rows + n_free_rows; pfree_i++) {
int i = -1, j;
size_t k = 0;
j = find_path_dense(n, cost, *pfree_i, y, v, pred);
if (j < 0)
{
throw std::runtime_error("Error occured in _ca_dense(): j < 0");
}
if (j >= static_cast<int>(n))
{
throw std::runtime_error("Error occured in _ca_dense(): j >= n");
}
while (i != *pfree_i) {
i = pred[j];
y[j] = i;
LAPJV_CPP_SWAP_INDICES(j, x[i]);
k++;
if (k >= n) {
throw std::runtime_error("Error occured in _ca_dense(): k >= n");
}
}
}
LAPJV_CPP_FREE(pred);
return 0;
}
}
/** Solve dense sparse LAP. */
int ByteTrack::lapjv_internal(
const size_t n, double *cost[],
int *x, int *y)
{
int ret;
int *free_rows;
double *v;
LAPJV_CPP_NEW(free_rows, int, n);
LAPJV_CPP_NEW(v, double, n);
ret = _ccrrt_dense(n, cost, free_rows, x, y, v);
int i = 0;
while (ret > 0 && i < 2) {
ret = _carr_dense(n, cost, ret, free_rows, x, y, v);
i++;
}
if (ret > 0) {
ret = _ca_dense(n, cost, ret, free_rows, x, y, v);
}
LAPJV_CPP_FREE(v);
LAPJV_CPP_FREE(free_rows);
return ret;
}
#undef LAPJV_CPP_NEW
#undef LAPJV_CPP_FREE
#undef LAPJV_CPP_SWAP_INDICES