-#include<stdio.h>
-#include<stdlib.h>
-#include<string.h>
-
-inline int clip(int v, int mn, int mx) { return v<mn ? mn : v>mx ? mx : v; }
-
-void hist_eq(unsigned char *dp, int len)
-{
- int hist[256], map[256];
- for( int i=0; i<256; ++i ) hist[i] = 0, map[i] = -1;
- unsigned char *bp = dp;
- for( int i=len; --i>=0; ++bp ) ++hist[*bp];
- double v = 0, dv = len/256.;
- for( int i=0,j=0,t=0; i<256; ++i ) {
- int k = v; v += dv;
- while( t < k ) { map[j] = i; t += hist[j++]; }
- }
-//for( int i=0; i<256; ++i ) fprintf(stderr,"%d\n",map[i]);
- for( int i=len; --i>=0; ++dp ) *dp = map[*dp];
-}
-
-int main(int ac, char **av)
-{
- FILE *ifp = !strcmp(av[1],"-") ? stdin : fopen(av[1],"r");
- FILE *ofp = !strcmp(av[2],"-") ? stdout : fopen(av[2],"w");
- char line[120];
- fgets(line,sizeof(line),ifp); fputs(line,ofp);
- fgets(line,sizeof(line),ifp); fputs(line,ofp);
- int w, h; if( sscanf(line,"%d %d\n",&w,&h) != 2 ) exit(1);
- fgets(line,sizeof(line),ifp); fputs(line,ofp);
- int len = w*h;
- unsigned char data[len], *bp = data;
- for( int ch, i=len; --i>=0 && (ch=getc(ifp)) >= 0; ++bp ) *bp = ch;
- for( int i=1; --i>=0; ) hist_eq(data,len);
- bp = data;
- for( int i=len; --i>=0; ++bp ) putc(*bp,ofp);
-
- if( ifp != stdin ) fclose(ifp);
- if( ofp != stdout ) fclose(ofp);
- return 0;
-}
-