// relevant structures

//  sections exist from "from" to "to" in a Counter-Clockwise manner
typedef struct section{
    double from;                        //  start angle
    double to;                          //  end   angle
} section;

// relevant functions

// returns angular distance from a1 counter-clockwise to a2
double getDistance(double a1, double a2){
    return getAngle(getAngle(a2) - getAngle(a1));
}

// ensures angle is between 0 and 360
double getAngle(double a){
    while(a < 0.0)      a += 360.0;
    while(a >= 360.0)    a -= 360.0;
    return a;
}

// problem function
void combineOverlaps(section* sections, int *numSections){

    int swapped,i,j;
    
    // combine sections that overlap
    swapped = 1;
    while(swapped){
        swapped = 0;
        for(i = 0 ; (i < *numSections && swapped == 0); i++){
            for(j = 0 ; (j < *numSections && swapped == 0); j++){
                if(i != j){
                    if(getDistance(sections[i].from,sections[i].to)
                       >=
                       getDistance(sections[i].from,sections[j].from)
                      ){
                        // combine the sections
                        if(getDistance(sections[i].from, sections[i].to)
                           <
                           getDistance(sections[i].from, sections[j].to)){
                                sections[i].to = sections[j].to;
                           }
                        // get rid of j
                        sections[j] = sections[*numSections - 1];
                        *numSections = *numSections - 1;
                        swapped = 1;
                    }
                }
            }
        }
    }
}

// problem function modified for debugging
// besides the added fprintf's I also changed it so
// that the two operands of the >= that is failing
// are being stored in doubles so that I can print
// them later without re-evaluating them.
void combineOverlaps(section* sections, int *numSections){

    int swapped,i,j;
    double dtmpa, dtmpb,dtmpc;
    
    fprintf(stderr,"\n");
    for(i = 0 ; i < *numSections; i++){
        fprintf(stderr,"Section %2d : %12f %12f\n",i,sections[i].from,sections[i].to);
    }

    // combine sections that overlap
    swapped = 1;
    while(swapped){
        fprintf(stderr,"swapped is true\n");
        fprintf(stderr,"Equality matrix...\n");
        // horizontal header
        fprintf(stderr,"  ");
        for(i = 0 ; i < *numSections; i++){
            fprintf(stderr,"%2d",i);
        }
        fprintf(stderr,"\n   ");
        for(i = 0 ; i < *numSections; i++){
            fprintf(stderr,"ft");
        }
        fprintf(stderr,"\n");
        
        // body
        for(i = 0 ; i < *numSections; i++){
            fprintf(stderr,"%2df",i);
            for(j = 0 ; j < *numSections; j++){
                fprintf(stderr,"%s",sections[i].from == sections[j].from ? "=" : ".");
                fprintf(stderr,"%s",sections[i].from == sections[j].to   ? "=" : ".");
            }
            fprintf(stderr,"\n");
            fprintf(stderr,"  t");
            for(j = 0 ; j < *numSections; j++){
                fprintf(stderr,"%s",sections[i].to   == sections[j].from ? "=" : ".");
                fprintf(stderr,"%s",sections[i].to   == sections[j].to   ? "=" : ".");
            }
            fprintf(stderr,"\n");
        }
        swapped = 0;
        for(i = 0 ; (i < *numSections && swapped == 0); i++){
            fprintf(stderr,"i : %d\n",i);
            for(j = 0 ; (j < *numSections && swapped == 0); j++){
                fprintf(stderr,"j : %d\n",j);
                if(i != j){
                    fprintf(stderr,"%d != %d\n",i,j);
                    dtmpa = getDistance(sections[i].from,sections[i].to);
                    dtmpb = getDistance(sections[i].from,sections[j].from);
                    if(dtmpa
                       >=
                       dtmpb
                      ){
                        fprintf(stderr,"getDistance(sections[%d].from (%20.15f),sections[%d].to   (%20.15f)) ... (%25.20f)\n",i,sections[i].from,i,sections[i].to  ,dtmpa);
                        fprintf(stderr,">=\n");
                        fprintf(stderr,"getDistance(sections[%d].from (%20.15f),sections[%d].from (%20.15f)) ... (%25.20f)\n",i,sections[i].from,j,sections[j].from,dtmpb);
                        // combine the sections
                        if(getDistance(sections[i].from, sections[i].to)
                           <
                           getDistance(sections[i].from, sections[j].to)){
                                sections[i].to = sections[j].to;
                           }
                        // get rid of j
                        sections[j] = sections[*numSections - 1];
                        *numSections = *numSections - 1;
                        swapped = 1;
                    }else{
                        fprintf(stderr,"getDistance(sections[%d].from (%20.15f),sections[%d].to   (%20.15f)) ... (%25.20f)\n",i,sections[i].from,i,sections[i].to  ,dtmpa);
                        if(dtmpa <  dtmpb) fprintf(stderr,"(< ) ");
                        if(dtmpa <= dtmpb) fprintf(stderr,"(<=) ");
                        if(dtmpa >  dtmpb) fprintf(stderr,"(> ) ");
                        if(dtmpa >= dtmpb) fprintf(stderr,"(UH OH) ");
                        if(dtmpa == dtmpb) fprintf(stderr,"(==) ");
                        fprintf(stderr,"<\n");
                        fprintf(stderr,"getDistance(sections[%d].from (%20.15f),sections[%d].from (%20.15f)) ... (%25.20f)\n",i,sections[i].from,j,sections[j].from,dtmpb);
                    }
                }
            }
        }
    }
}