r935:6ea176638264
Tue, 15 Mar 2011 19:16:20
[Not Reviewed]
0 comments (0 inline)
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| ... | ... |
@@ -1103,16 +1103,15 @@ |
| 1103 | 1103 |
void startAugment(int max_length) {
|
| 1104 | 1104 |
// Paramters for heuristics |
| 1105 | 1105 |
const int EARLY_TERM_EPSILON_LIMIT = 1000; |
| 1106 |
const double GLOBAL_UPDATE_FACTOR = 3.0; |
|
| 1107 |
|
|
| 1108 |
const |
|
| 1106 |
const double GLOBAL_UPDATE_FACTOR = 1.0; |
|
| 1107 |
const int global_update_skip = static_cast<int>(GLOBAL_UPDATE_FACTOR * |
|
| 1109 | 1108 |
(_res_node_num + _sup_node_num * _sup_node_num)); |
| 1110 |
int next_update_limit = global_update_freq; |
|
| 1111 |
|
|
| 1112 |
int |
|
| 1109 |
int next_global_update_limit = global_update_skip; |
|
| 1113 | 1110 |
|
| 1114 | 1111 |
// Perform cost scaling phases |
| 1115 |
|
|
| 1112 |
IntVector path; |
|
| 1113 |
BoolVector path_arc(_res_arc_num, false); |
|
| 1114 |
int relabel_cnt = 0; |
|
| 1116 | 1115 |
for ( ; _epsilon >= 1; _epsilon = _epsilon < _alpha && _epsilon > 1 ? |
| 1117 | 1116 |
1 : _epsilon / _alpha ) |
| 1118 | 1117 |
{
|
| ... | ... |
@@ -1135,32 +1134,45 @@ |
| 1135 | 1134 |
int start = _active_nodes.front(); |
| 1136 | 1135 |
|
| 1137 | 1136 |
// Find an augmenting path from the start node |
| 1138 |
path.clear(); |
|
| 1139 | 1137 |
int tip = start; |
| 1140 |
while ( |
|
| 1138 |
while (int(path.size()) < max_length && _excess[tip] >= 0) {
|
|
| 1141 | 1139 |
int u; |
| 1142 |
LargeCost |
|
| 1140 |
LargeCost rc, min_red_cost = std::numeric_limits<LargeCost>::max(); |
|
| 1141 |
LargeCost pi_tip = _pi[tip]; |
|
| 1143 | 1142 |
int last_out = _first_out[tip+1]; |
| 1144 | 1143 |
for (int a = _next_out[tip]; a != last_out; ++a) {
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| 1145 |
u = _target[a]; |
|
| 1146 |
if (_res_cap[a] > 0 && _cost[a] + pi_tip - _pi[u] < 0) {
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|
| 1147 |
path.push_back(a); |
|
| 1148 |
_next_out[tip] = a; |
|
| 1149 |
tip = u; |
|
| 1150 |
goto next_step; |
|
| 1144 |
if (_res_cap[a] > 0) {
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|
| 1145 |
u = _target[a]; |
|
| 1146 |
rc = _cost[a] + pi_tip - _pi[u]; |
|
| 1147 |
if (rc < 0) {
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| 1148 |
path.push_back(a); |
|
| 1149 |
_next_out[tip] = a; |
|
| 1150 |
if (path_arc[a]) {
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|
| 1151 |
goto augment; // a cycle is found, stop path search |
|
| 1152 |
} |
|
| 1153 |
tip = u; |
|
| 1154 |
path_arc[a] = true; |
|
| 1155 |
goto next_step; |
|
| 1156 |
} |
|
| 1157 |
else if (rc < min_red_cost) {
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|
| 1158 |
min_red_cost = rc; |
|
| 1159 |
} |
|
| 1151 | 1160 |
} |
| 1152 | 1161 |
} |
| 1153 | 1162 |
|
| 1154 | 1163 |
// Relabel tip node |
| 1155 |
min_red_cost = std::numeric_limits<LargeCost>::max(); |
|
| 1156 | 1164 |
if (tip != start) {
|
| 1157 | 1165 |
int ra = _reverse[path.back()]; |
| 1158 |
min_red_cost = |
|
| 1166 |
min_red_cost = |
|
| 1167 |
std::min(min_red_cost, _cost[ra] + pi_tip - _pi[_target[ra]]); |
|
| 1159 | 1168 |
} |
| 1169 |
last_out = _next_out[tip]; |
|
| 1160 | 1170 |
for (int a = _first_out[tip]; a != last_out; ++a) {
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| 1161 |
rc = _cost[a] + pi_tip - _pi[_target[a]]; |
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| 1162 |
if (_res_cap[a] > 0 && rc < min_red_cost) {
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| 1163 |
|
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| 1171 |
if (_res_cap[a] > 0) {
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| 1172 |
rc = _cost[a] + pi_tip - _pi[_target[a]]; |
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| 1173 |
if (rc < min_red_cost) {
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| 1174 |
min_red_cost = rc; |
|
| 1175 |
} |
|
| 1164 | 1176 |
} |
| 1165 | 1177 |
} |
| 1166 | 1178 |
_pi[tip] -= min_red_cost + _epsilon; |
| ... | ... |
@@ -1169,7 +1181,9 @@ |
| 1169 | 1181 |
|
| 1170 | 1182 |
// Step back |
| 1171 | 1183 |
if (tip != start) {
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| 1172 |
|
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| 1184 |
int pa = path.back(); |
|
| 1185 |
path_arc[pa] = false; |
|
| 1186 |
tip = _source[pa]; |
|
| 1173 | 1187 |
path.pop_back(); |
| 1174 | 1188 |
} |
| 1175 | 1189 |
|
| ... | ... |
@@ -1177,28 +1191,34 @@ |
| 1177 | 1191 |
} |
| 1178 | 1192 |
|
| 1179 | 1193 |
// Augment along the found path (as much flow as possible) |
| 1194 |
augment: |
|
| 1180 | 1195 |
Value delta; |
| 1181 | 1196 |
int pa, u, v = start; |
| 1182 | 1197 |
for (int i = 0; i != int(path.size()); ++i) {
|
| 1183 | 1198 |
pa = path[i]; |
| 1184 | 1199 |
u = v; |
| 1185 | 1200 |
v = _target[pa]; |
| 1201 |
path_arc[pa] = false; |
|
| 1186 | 1202 |
delta = std::min(_res_cap[pa], _excess[u]); |
| 1187 | 1203 |
_res_cap[pa] -= delta; |
| 1188 | 1204 |
_res_cap[_reverse[pa]] += delta; |
| 1189 | 1205 |
_excess[u] -= delta; |
| 1190 | 1206 |
_excess[v] += delta; |
| 1191 |
if (_excess[v] > 0 && _excess[v] <= delta) |
|
| 1207 |
if (_excess[v] > 0 && _excess[v] <= delta) {
|
|
| 1192 | 1208 |
_active_nodes.push_back(v); |
| 1209 |
} |
|
| 1193 | 1210 |
} |
| 1211 |
path.clear(); |
|
| 1194 | 1212 |
|
| 1195 | 1213 |
// Global update heuristic |
| 1196 |
if (relabel_cnt >= |
|
| 1214 |
if (relabel_cnt >= next_global_update_limit) {
|
|
| 1197 | 1215 |
globalUpdate(); |
| 1198 |
|
|
| 1216 |
next_global_update_limit += global_update_skip; |
|
| 1199 | 1217 |
} |
| 1200 | 1218 |
} |
| 1219 |
|
|
| 1201 | 1220 |
} |
| 1221 |
|
|
| 1202 | 1222 |
} |
| 1203 | 1223 |
|
| 1204 | 1224 |
/// Execute the algorithm performing push and relabel operations |
| ... | ... |
@@ -1207,15 +1227,14 @@ |
| 1207 | 1227 |
const int EARLY_TERM_EPSILON_LIMIT = 1000; |
| 1208 | 1228 |
const double GLOBAL_UPDATE_FACTOR = 2.0; |
| 1209 | 1229 |
|
| 1210 |
const int |
|
| 1230 |
const int global_update_skip = static_cast<int>(GLOBAL_UPDATE_FACTOR * |
|
| 1211 | 1231 |
(_res_node_num + _sup_node_num * _sup_node_num)); |
| 1212 |
int next_update_limit = global_update_freq; |
|
| 1213 |
|
|
| 1214 |
int |
|
| 1232 |
int next_global_update_limit = global_update_skip; |
|
| 1215 | 1233 |
|
| 1216 | 1234 |
// Perform cost scaling phases |
| 1217 | 1235 |
BoolVector hyper(_res_node_num, false); |
| 1218 | 1236 |
LargeCostVector hyper_cost(_res_node_num); |
| 1237 |
int relabel_cnt = 0; |
|
| 1219 | 1238 |
for ( ; _epsilon >= 1; _epsilon = _epsilon < _alpha && _epsilon > 1 ? |
| 1220 | 1239 |
1 : _epsilon / _alpha ) |
| 1221 | 1240 |
{
|
| ... | ... |
@@ -1293,9 +1312,11 @@ |
| 1293 | 1312 |
min_red_cost = hyper[n] ? -hyper_cost[n] : |
| 1294 | 1313 |
std::numeric_limits<LargeCost>::max(); |
| 1295 | 1314 |
for (int a = _first_out[n]; a != last_out; ++a) {
|
| 1296 |
rc = _cost[a] + pi_n - _pi[_target[a]]; |
|
| 1297 |
if (_res_cap[a] > 0 && rc < min_red_cost) {
|
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| 1298 |
|
|
| 1315 |
if (_res_cap[a] > 0) {
|
|
| 1316 |
rc = _cost[a] + pi_n - _pi[_target[a]]; |
|
| 1317 |
if (rc < min_red_cost) {
|
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| 1318 |
min_red_cost = rc; |
|
| 1319 |
} |
|
| 1299 | 1320 |
} |
| 1300 | 1321 |
} |
| 1301 | 1322 |
_pi[n] -= min_red_cost + _epsilon; |
| ... | ... |
@@ -1313,11 +1334,11 @@ |
| 1313 | 1334 |
} |
| 1314 | 1335 |
|
| 1315 | 1336 |
// Global update heuristic |
| 1316 |
if (relabel_cnt >= |
|
| 1337 |
if (relabel_cnt >= next_global_update_limit) {
|
|
| 1317 | 1338 |
globalUpdate(); |
| 1318 | 1339 |
for (int u = 0; u != _res_node_num; ++u) |
| 1319 | 1340 |
hyper[u] = false; |
| 1320 |
|
|
| 1341 |
next_global_update_limit += global_update_skip; |
|
| 1321 | 1342 |
} |
| 1322 | 1343 |
} |
| 1323 | 1344 |
} |
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