1 files changed, 54 insertions, 0 deletions
diff --git a/src/prioq.c b/src/prioq.c
new file mode 100644
index 0000000..9559d31
--- /dev/null
+++ b/src/prioq.c
@@ -0,0 +1,54 @@
+#include "alloc.h"
+#include "genalloc.h"
+#include "prioq.h"
+
+GEN_ALLOC_readyplus(prioq,struct prioq_elt,p,len,a,i,n,x,100,prioq_readyplus)
+
+int prioq_insert(prioq *pq, struct prioq_elt *pe)
+{
+  int i;
+  int j;
+
+  if (!prioq_readyplus(pq,1)) return 0;
+  j = pq->len++;
+  while (j) {
+    i = (j - 1)/2;
+    if (pq->p[i].dt <= pe->dt) break;
+    pq->p[j] = pq->p[i];
+    j = i;
+  }
+  pq->p[j] = *pe;
+  return 1;
+}
+
+int prioq_min(prioq *pq, struct prioq_elt *pe)
+{
+  if (!pq->p) return 0;
+  if (!pq->len) return 0;
+  *pe = pq->p[0];
+  return 1;
+}
+
+void prioq_delmin(prioq *pq)
+{
+  int i;
+  int j;
+  int n;
+
+  if (!pq->p) return;
+  n = pq->len;
+  if (!n) return;
+  i = 0;
+  --n;
+
+  for (;;) {
+    j = i + i + 2;
+    if (j > n) break;
+    if (pq->p[j - 1].dt <= pq->p[j].dt) --j;
+    if (pq->p[n].dt <= pq->p[j].dt) break;
+    pq->p[i] = pq->p[j];
+    i = j;
+  }
+ pq->p[i] = pq->p[n];
+ pq->len = n;
+}