diff --git a/A1/id_query_indexed b/A1/id_query_indexed
new file mode 100755
index 0000000..82d7823
Binary files /dev/null and b/A1/id_query_indexed differ
diff --git a/A1/id_query_indexed.c b/A1/id_query_indexed.c
new file mode 100644
index 0000000..9028cd2
--- /dev/null
+++ b/A1/id_query_indexed.c
@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <stdint.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "record.h"
+#include "id_query.h"
+
+struct index_record {
+    int64_t osm_id;
+    const struct record* record;
+};
+
+struct indexed_data {
+    struct index_record* irs;
+    int n;
+};
+
+struct indexed_data* mk_indexed(struct record* rs, int n) {
+    struct index_record irs[n];
+    for (int i = 0 ; i < n ; i++) {
+        struct record* rec = &rs[i];
+        struct index_record irec = { .osm_id = rec->osm_id, .record = rec };
+        irs[i] = irec;
+    }
+    struct indexed_data* data = malloc(sizeof(struct indexed_data*));
+    data->irs = irs;
+    data->n = n;
+    return data;
+}
+
+void free_indexed(struct indexed_data* data) {
+    struct record* rs = malloc(sizeof(struct record*));
+    int n = data->n;
+    for (int i = 0 ; i < n ; i++) {
+        struct index_record* irec = &data->irs[i];
+        rs[i] = *irec->record;
+    }
+    free_records(rs, n);
+}
+
+const struct record* lookup_indexed(struct indexed_data *data, int64_t needle) {
+    int n = data->n;
+    for (int i = 0 ; i < n ; i++) {
+        struct index_record* irec = &data->irs[i];
+        if (irec->osm_id == needle) {
+            return irec->record;
+        }
+    }
+    return NULL;
+}
+
+int main(int argc, char** argv) {
+    return id_query_loop(argc, argv,
+                                        (mk_index_fn)mk_indexed,
+                                        (free_index_fn)free_indexed,
+                                        (lookup_fn)lookup_indexed);
+}
diff --git a/A1/id_query_naive b/A1/id_query_naive
index 86e67b9..9c136e6 100755
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