diff options
Diffstat (limited to '01-knapsack/1-relaxation-what-to-do-with.patch')
| -rw-r--r-- | 01-knapsack/1-relaxation-what-to-do-with.patch | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/01-knapsack/1-relaxation-what-to-do-with.patch b/01-knapsack/1-relaxation-what-to-do-with.patch new file mode 100644 index 0000000..cbc59e3 --- /dev/null +++ b/01-knapsack/1-relaxation-what-to-do-with.patch @@ -0,0 +1,143 @@ +diff --git a/01-knapsack/ks_dp-ng.c b/01-knapsack/ks_dp-ng.c +index 7830651..ddb0d04 100644 +--- a/01-knapsack/ks_dp-ng.c ++++ b/01-knapsack/ks_dp-ng.c +@@ -7,12 +7,14 @@ + + #define NONE -1 + ++enum { RELAX = 0, NO_RELAX }; + enum { SORT_DESC = 0, SORT_ASC }; + enum { UNSORTED = 0, SORT_WR, SORT_VR, SORT_RW, SORT_RV}; + + static int debug; + static int sort; + static int sort_order; ++static int relax; + + typedef struct _InputItem + { +@@ -25,6 +27,7 @@ typedef struct _SolverItem { + int i; /* index of the selected item */ + int v; /* cumulated value */ + int w; /* cumulated weight */ ++ float r; /* linear relaxation best value */ + } SolverItem; + + typedef struct _Solver +@@ -87,11 +90,39 @@ item_cmp(const void *p1, const void *p2) + return 0; + } + ++static inline float relax_item(Solver* solver, SolverItem* data, int start) ++{ ++ int w; ++ int i; ++ float relax; ++ const InputItem *item; ++ ++ w = data->w; ++ relax= data->v; ++ item = &solver->items[start]; ++ for (i = start; i < solver->n; i++, item++) ++ { ++ if ((w + item->w) <= solver->k) ++ { ++ w += item->w; ++ relax += item->v; ++ } ++ else ++ { ++ relax += (item->v * ((solver->k - w) / (float)item->w)); ++ break; ++ } ++ } ++ ++ return relax; ++} ++ + static void solve(Solver* solver) + { + int n, k; + int v, w; + int i, j; ++ float r; + int min_c, lower_bound; + const InputItem *item; + SolverItem *data; +@@ -105,7 +136,16 @@ static void solve(Solver* solver) + + if (debug > 2) + { +- printf("\nformat V(i,W)\n"); ++ printf("\nformat V(i,W,r)\n"); ++ } ++ ++ /* RELAXATION */ ++ if (relax == RELAX) ++ { ++ data = solver->column; ++ r = relax_item(solver, data, 0); ++ for (j = 0; j <= k; j++, data++) ++ data->r = r; + } + + /* SOLVE */ +@@ -134,6 +174,12 @@ static void solve(Solver* solver) + data->v = v + up_left->v; + data->w = w + up_left->w; + } ++ ++ /* RELAXTION must be cached */ ++ if (relax == RELAX) ++ { ++ data->r = relax_item(solver, data, (i + 1)); ++ } + } + + if (debug > 2) +@@ -141,8 +187,8 @@ static void solve(Solver* solver) + printf("i=%d; j=k; j<=%d:\n", i, lower_bound); + data = solver->column; + for (j = 0; j <= k; j++, data++) +- printf(" %d : % 4d(% 2d % 2d)\n", +- j, data->v, data->i, data->w); ++ printf(" %d : % 4d(% 2d % 2d %.1f)\n", ++ j, data->v, data->i, data->w, data->r); + printf("\n"); + } + } +@@ -152,8 +198,8 @@ static void solve(Solver* solver) + printf("i=%d:\n", solver->n - 1); + data = solver->column; + for (j = 0; j <= k; j++, data++) +- printf(" % 4d(% 2d % 2d)\n", +- data->v, data->i, data->w); ++ printf(" % 4d(% 2d % 2d %.1f)\n", ++ data->v, data->i, data->w, data->r); + } + + if (debug > 0) +@@ -194,10 +240,11 @@ int main(int argc, char** argv, char** env) + InputItem *item; + + debug = 0; ++ relax = NO_RELAX; + sort = UNSORTED; + sort_order = SORT_DESC; + excpected_value = NONE; +- while ((opt = getopt(argc, argv, "d:e:s:S")) != -1) { ++ while ((opt = getopt(argc, argv, "d:e:s:SR")) != -1) { + switch (opt) { + case 'd': + debug = atoi(optarg); +@@ -211,6 +258,9 @@ int main(int argc, char** argv, char** env) + case 'S': + sort_order = SORT_ASC; + break; ++ case 'R': ++ relax = RELAX; ++ break; + default: /* '?' */ + fprintf(stderr, "Usage: %s [falgs] input\n", + argv[0]); |