give up on C

Dockerfile

@@ -12,6 +12,7 @@ RUN apt update -y && apt install -y --no-install-recommends \
     clang \
     curl \
     direnv \
+    gdb \
     git \
     libomp-dev \
     libopenmpi-dev \
@@ -31,6 +32,6 @@ COPY --from=typst /bin/typst /usr/bin/typst
 
 RUN curl https://sh.rustup.rs -sSf | bash -s -- -y
 RUN /root/.cargo/bin/cargo install cargo-watch
-RUN /root/.cargo/bin/cargo install watchexec
+# RUN /root/.cargo/bin/cargo install watchexec-cli
 
 RUN echo 'eval "$(direnv hook bash)"' >> /root/.bashrc

assignments/03/Makefile

@@ -1,6 +1,6 @@
 .PHONY: run clean
 
-CFLAGS += -O3
+CFLAGS += -g
 # CFLAGS += -DFMT_HEADER_ONLY -g
 # LDFLAGS += $(shell pkg-config --libs fmt)
 

assignments/03/lpa.cpp

@@ -1,8 +1,3 @@
-#include <algorithm>
-#include <array>
-#include <cstring>
-#include <functional>
-#include <limits>
 #include <map>
 #include <set>
 #include <vector>
@@ -12,7 +7,6 @@
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
-#include <utility>
 
 #ifdef FMT_HEADER_ONLY
 #include <fmt/format.h>
@@ -182,7 +176,6 @@ int main(int argc, char **argv) {
 // of the graph.
 #pragma region
   int node_label_assignment_vec[num_my_nodes];
-  // std::map<int, int> node_label_assignment;
   pair my_node_range = node_ranges[rank];
 
   // Initial node assignment
@@ -246,12 +239,11 @@ int main(int argc, char **argv) {
 #pragma region
   while (true) {
     // First, exchange the data that needs to be exchanged
-    std::vector<int> sendbuf;
-    std::vector<int> send_counts;
-    std::vector<int> send_displs;
-    std::vector<int> recv_counts;
-    std::vector<int> recv_displs;
-    std::vector<int> recvbuf;
+    int sendbuf[num_my_nodes];
+    int send_counts[p];
+    int send_displs[p];
+    int recv_counts[p];
+    int recv_displs[p];
     std::map<int, int> remote_labels;
 
     if (p > 1) {
@@ -262,28 +254,27 @@ int main(int argc, char **argv) {
         for (int i = 0; i < p; ++i) {
           int count = send_map[i].size();
           for (auto local_node : send_map[i]) {
-            sendbuf.push_back(
-                node_label_assignment_vec[local_node - my_node_range.fst]);
+            sendbuf[offset + local_node - my_node_range.fst] =
+                node_label_assignment_vec[local_node - my_node_range.fst];
           }
-          send_counts.push_back(count);
-          send_displs.push_back(offset);
+          send_counts[i] = count;
+          send_displs[i] = offset;
           offset += count;
         }
 
         offset = 0;
         for (int i = 0; i < p; ++i) {
           int count = recv_map[i].size();
-          recv_counts.push_back(count);
-          recv_displs.push_back(offset);
+          recv_counts[i] = count;
+          recv_displs[i] = offset;
           offset += count;
         }
         recv_total = offset;
       }
 
-      recvbuf = std::vector<int>(recv_total, 0);
-      MPI_Alltoallv(sendbuf.data(), send_counts.data(), send_displs.data(),
-                    MPI_INT, recvbuf.data(), recv_counts.data(),
-                    recv_displs.data(), MPI_INT, MPI_COMM_WORLD);
+      int recvbuf[recv_total];
+      MPI_Alltoallv(sendbuf, send_counts, send_displs, MPI_INT, recvbuf,
+                    recv_counts, recv_displs, MPI_INT, MPI_COMM_WORLD);
 
       // Cache efficiently
       for (int i = 0; i < p; ++i) {
@@ -369,8 +360,6 @@ int main(int argc, char **argv) {
       int count = this_node_range.snd - this_node_range.fst;
       if (process_idx == 0) {
         for (int j = 0; j < count; ++j) {
-          // all_assignments[this_node_range.fst + j] =
-          //     node_label_assignment_vec[j];
           fprintf(fp, "%d\n", node_label_assignment_vec[j]);
           label_count[node_label_assignment_vec[j]]++;
         }
@@ -384,6 +373,9 @@ int main(int argc, char **argv) {
         }
       }
     }
+
+    printf("%d\n", label_count.size());
+
   } else {
     MPI_Send(node_label_assignment_vec, num_my_nodes, MPI_INT, 0,
              TAG_SEND_FINAL_RESULT, MPI_COMM_WORLD);
@@ -456,30 +448,33 @@ int lookup_assignment(int *base_node_assignment, pair my_node_range,
   int index = -1, ctr = 0;
   std::vector<int> inner(recv_map[process_from].begin(),
                          recv_map[process_from].end());
-  // {
-  //   int lo = 0, hi = count;
-  //   while (lo < hi) {
-  //     int mid = (lo + hi) / 2;
-  //     int midk = inner[mid];
-  //     if (node_number < midk)
-  //       hi = mid;
-  //     else if (node_number > midk)
-  //       lo = mid;
-  //     else {
-  //       index = mid;
-  //       break;
-  //     }
-  //   }
-  // }
-  for (int i = 0; i < count; ++i) {
-    int remote_node = inner[i];
-    if (node_number == remote_node) {
-      index = ctr;
-      break;
+
+  {
+    // Use binary search...
+    int lo = 0, hi = count;
+    while (lo < hi) {
+      int mid = (lo + hi) / 2;
+      int midk = inner[mid];
+      if (node_number < midk)
+        hi = mid;
+      else if (node_number > midk)
+        lo = mid;
+      else {
+        index = mid;
+        break;
+      }
     }
-    ctr++;
   }
 
+  // for (int i = 0; i < count; ++i) {
+  //   int remote_node = inner[i];
+  //   if (node_number == remote_node) {
+  //     index = ctr;
+  //     break;
+  //   }
+  //   ctr++;
+  // }
+
   // Pull the corresponding value from the map
   return recvbuf[recv_displs[process_from] + index];
 }

assignments/03/test.gdb

@@ -1,5 +1,5 @@
 set pagination off
-run dataset/both_1000.txt
+run dataset/both_1000.txt out.txt
 bt
 frame 3
 print k