diff --git a/algo/local_improving.cpp b/algo/local_improving.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..06484a7caf31a5d514136f893ce96dc92f7cf768
--- /dev/null
+++ b/algo/local_improving.cpp
@@ -0,0 +1,64 @@
+#include "../pipe.h"
+#include <functional>
+#include <cassert>
+
+// ****** ARGS ********
+// <int> max number of changes
+
+using std::pair;
+
+const int VERSION = 2;
+const bool ALLOW_INPUT_MISTAKES = 0;
+const bool ALLOW_MISTAKES = 0;
+
+vector<bool> solve(int n, vector<int> input, vector<bool> out,
+ int argc, char const* const* argv)
+{
+ assert(argc==1);
+ int max_changes = atoi(argv[0]);
+ assert(max_changes > 0);
+
+ vector<int> other = lib::gen_arr_other_car_of_type(n, input);
+
+ std::function<bool (int, int , int)> f = [&](int changes, int score_diff, int begin_index)
+ {
+ for(int i=begin_index; i<2*n;i++) if(i < other[i])
+ {
+ out[i] = !out[i];
+ out[other[i]] = !out[other[i]];
+
+ int new_score_diff = score_diff;
+ if(i) new_score_diff += out[i]==out[i-1] ? -1 : 1;
+ if(i+1 != other[i])
+ {
+ new_score_diff += out[i]==out[i+1] ? -1 : 1;
+ new_score_diff += out[other[i]]==out[other[i]-1] ? -1 : 1;
+ }
+ if(other[i]!=2*n-1) new_score_diff += out[other[i]]==out[other[i]+1] ? -1 : 1;
+
+ if(new_score_diff < 0)
+ {
+ fprintf(stderr, "%d %d %d\n", changes, i, new_score_diff);
+ return true;
+ }
+
+
+ if(changes+1 < max_changes)
+ if(f(changes+1, new_score_diff, i+1))
+ return true;
+
+ out[i] = !out[i];
+ out[other[i]] = !out[other[i]];
+ }
+ return false;
+ };
+
+ while (f(0, 0, 0))
+ {
+
+ fo(i, 2*n) fprintf(stderr, "%c", out[i]?'1':'0');
+ fprintf(stderr, "\n", n);
+ }
+
+ return out;
+}
diff --git a/algo/rg.cpp b/algo/rg.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..81b769d4c394700e7267229ad5aa60b4ed3ceabf
--- /dev/null
+++ b/algo/rg.cpp
@@ -0,0 +1,42 @@
+#include "../main.h"
+
+const int VERSION = 1;
+const bool ALLOW_MISTAKES = 0;
+
+vector<bool> solve(int n, vector<int> input,
+ int argc, char const* const* argv)
+{
+ if(n == 0) return vector<bool>();
+ vector<int> other = lib::gen_arr_other_car_of_type(n, input);
+ vector<bool> out(2*n);
+
+ vector<int> r_input(2*n-2);
+ for(int i=1;i<2*n;i++) if(i != other[0])
+ r_input[i - 1 - (i>other[0])] = input[i] - (input[i] > input[0]);
+
+ auto r_out = solve(n-1, r_input, argc, argv);
+
+ for(int i=1;i<2*n;i++) if(i != other[0])
+ out[i] = r_out[i - 1 - (i>other[0])];
+
+ if(other[0] == 2*n-1)
+ {
+ out[0] = 1;
+ out[other[0]] = 0;
+ }
+ else if(other[0] == 1)
+ {
+ out[0] = !out[2];
+ out[1] = out[2];
+ }
+ else
+ {
+ if(out[other[0]-1] == out[1] && out[other[0]+1] == out[1])
+ out[0] = !out[1];
+ else
+ out[0] = out[1];
+ out[other[0]] = !out[0];
+ }
+
+ return out;
+}
diff --git a/algo/rsg.cpp b/algo/rsg.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..47895a2fba073a73fbabaaa3c11f87882074509f
--- /dev/null
+++ b/algo/rsg.cpp
@@ -0,0 +1,96 @@
+#include "../main.h"
+
+const int VERSION = 1;
+const bool ALLOW_MISTAKES = 0;
+
+
+vector<int> solve_star(int n, vector<int> input)
+{
+ if(n == 0) return vector<int>();
+ vector<int> other = lib::gen_arr_other_car_of_type(n, input);
+ vector<int> out(2*n); // 0: * -1, 1: colors
+
+ vector<int> r_input(2*n-2);
+ for(int i=1;i<2*n;i++) if(i != other[0])
+ r_input[i - 1 - (i>other[0])] = input[i] - (input[i] > input[0]);
+
+ auto r_out = solve_star(n-1, r_input);
+
+ for(int i=1;i<2*n;i++) if(i != other[0])
+ out[i] = r_out[i - 1 - (i>other[0])];
+
+ if(other[0] == 2*n-1) // B
+ {
+ out[0] = 1;
+ out[other[0]] = -1;
+ }
+ else if(other[0] == 1) // A
+ {
+ out[0] = -out[2];
+ out[1] = out[2];
+ }
+ else if(out[other[0]-1] == out[other[0]+1] && out[other[0]-1]) // C
+ {
+ out[0] = -out[other[0]-1];
+ out[other[0]] = out[other[0]-1];
+ }
+ else if(out[other[0]+1] && out[other[0]-1]) // D
+ {
+ out[0] = out[1];
+ out[other[0]] = -out[1];
+ }
+ else if(out[1] == -out[other[0]-1] || out[1] == -out[other[0]+1]) // E
+ {
+ out[0] = out[1];
+ out[other[0]] = -out[1];
+ }
+ else // F
+ {
+ out[0] = out[1];
+ out[other[0]] = -out[1];
+ if(!out[other[0]-1])
+ {
+ out[other[0]-1] = -out[1];
+ out[other[other[0]-1]] = out[1];
+ }
+ else
+ {
+ out[other[0]+1] = -out[1];
+ out[other[other[0]+1]] = out[1];
+ }
+ }
+
+ if(other[1] != 2 && other[1] != 2*n-1
+ && out[1-1] && out[1+1]
+ && out[other[1]-1] && out[other[1]+1]) // G
+ {
+ int diffs = 0;
+ diffs += out[1] != out[1-1];
+ diffs += out[1] != out[1+1];
+ diffs += out[other[1]] != out[other[1]-1];
+ diffs += out[other[1]] != out[other[1]+1];
+ if(diffs == 2)
+ {
+ out[1] = out[other[1]] = 0;
+ }
+ }
+ //fo(i, 2*n) fprintf(stderr, "%c", out[i]?out[i]==1?'1':'0':'*');
+ //fprintf(stderr, "\n", n);
+ return out;
+}
+
+vector<bool> solve(int n, vector<int> input,
+ int argc, char const* const* argv)
+{
+ vector<int> other = lib::gen_arr_other_car_of_type(n, input);
+ auto out_star = solve_star(n, input);
+ vector<bool> out(2*n);
+ fo(i, 2*n)
+ {
+ if(out_star[i])
+ out[i] = out_star[i] > 0;
+ else
+ out[i] = i > other[i];
+ }
+ return out;
+}
diff --git a/build.mk b/build.mk
index 9c8685ab1aed390a5c8e3a3d5332d15d84d8cc0b..1eb333fcceb69a6ec6dbb74139ab9c947ce14f18 100644
--- a/build.mk
+++ b/build.mk
@@ -58,7 +58,10 @@ endef
$(eval $(call standard_algo,greedy))
$(eval $(call standard_algo,maxcut))
$(eval $(call standard_algo,semidef_prog))
+$(eval $(call standard_algo,rg))
+$(eval $(call standard_algo,rsg))
$(eval $(call standard_pipe,fix_naive))
$(eval $(call standard_pipe,fix_better))
+$(eval $(call standard_pipe,local_improving))
diff --git a/config.mk b/config.mk
index 0a26bc792f1e659c08f071f96645a2d0ba3760a2..732f4d3c2590167c25f3cb5d5035a55b0aff9bea 100644
--- a/config.mk
+++ b/config.mk
@@ -1 +1 @@
-algorithms=greedy maxcut fix_naive fix_better semidef_prog
+algorithms=greedy maxcut fix_naive fix_better semidef_prog local_improving rg rsg