add numerical recipes library

lib/nr/k_and_r/recipes/hufmak.c

@@ -0,0 +1,67 @@
+
+#include "nrutil.h"
+
+typedef struct {
+	unsigned long *icod,*ncod,*left,*right,nch,nodemax;
+} huffcode;
+
+void hufmak(nfreq,nchin,ilong,nlong,hcode)
+huffcode *hcode;
+unsigned long *ilong,*nlong,nchin,nfreq[];
+{
+	void hufapp();
+	int ibit;
+	long node,*up;
+	unsigned long j,k,*index,n,nused,*nprob;
+	static unsigned long setbit[32]={0x1L,0x2L,0x4L,0x8L,0x10L,0x20L,
+		0x40L,0x80L,0x100L,0x200L,0x400L,0x800L,0x1000L,0x2000L,
+		0x4000L,0x8000L,0x10000L,0x20000L,0x40000L,0x80000L,0x100000L,
+		0x200000L,0x400000L,0x800000L,0x1000000L,0x2000000L,0x4000000L,
+		0x8000000L,0x10000000L,0x20000000L,0x40000000L,0x80000000L};
+
+	hcode->nch=nchin;
+	index=lvector(1,(long)(2*hcode->nch-1));
+	up=(long *)lvector(1,(long)(2*hcode->nch-1));
+	nprob=lvector(1,(long)(2*hcode->nch-1));
+	for (nused=0,j=1;j<=hcode->nch;j++) {
+		nprob[j]=nfreq[j];
+		hcode->icod[j]=hcode->ncod[j]=0;
+		if (nfreq[j]) index[++nused]=j;
+	}
+	for (j=nused;j>=1;j--) hufapp(index,nprob,nused,j);
+	k=hcode->nch;
+	while (nused > 1) {
+		node=index[1];
+		index[1]=index[nused--];
+		hufapp(index,nprob,nused,1);
+		nprob[++k]=nprob[index[1]]+nprob[node];
+		hcode->left[k]=node;
+		hcode->right[k]=index[1];
+		up[index[1]] = -(long)k;
+		up[node]=index[1]=k;
+		hufapp(index,nprob,nused,1);
+	}
+	up[hcode->nodemax=k]=0;
+	for (j=1;j<=hcode->nch;j++) {
+		if (nprob[j]) {
+			for (n=0,ibit=0,node=up[j];node;node=up[node],ibit++) {
+				if (node < 0) {
+					n |= setbit[ibit];
+					node = -node;
+				}
+			}
+			hcode->icod[j]=n;
+			hcode->ncod[j]=ibit;
+		}
+	}
+	*nlong=0;
+	for (j=1;j<=hcode->nch;j++) {
+		if (hcode->ncod[j] > *nlong) {
+			*nlong=hcode->ncod[j];
+			*ilong=j-1;
+		}
+	}
+	free_lvector(nprob,1,(long)(2*hcode->nch-1));
+	free_lvector((unsigned long *)up,1,(long)(2*hcode->nch-1));
+	free_lvector(index,1,(long)(2*hcode->nch-1));
+}