//Clayton Colwell
//10.2.12
//Assignment 6

#include <stdio.h>
#include <stdlib.h>

double** create2dArray(int, int); //Create array of width, height

int getMenuChoice(int, int, char[]); //Get int between x and y with prompt
int compare_doubles(const void*, const void*); //Compare doubles for sort
double calcMean(double*, int); //Calculate mean of dataset of size
double calcStdDev(double*, int); //Calculate std dev of dataset of size
double** calcMode(double*, int); //Calculate mode of dataset of size (Mode may be multiple values=>array)
double calcRange(double*, int); //Calculate range of dataset of size


int main() {
    const int MAX_DATA = 50; //Max size of stats array
    int userN = 0; //# of points user wants to enter
    int menuSelection = 0; //Menu Selection 1Mean,2Std.Dev,3Mod,4Range,5Restart/Exit

    //Welcome and get userN (Loop until valid)
    printf("############# Welcome to the Statistical Calculator #############\n");
    printf("Note: This program can only accept up to %d data points.\n", MAX_DATA);
    userN = getMenuChoice(1, MAX_DATA, "\nNumber of data points: ");

    //Declare data array
    double* dataSet = calloc(userN - 1, sizeof(double*));

    //Fill array
    int inputCount;
    for(inputCount = 0; inputCount < userN; inputCount++) {
          printf("Input %d: ", inputCount + 1);
          scanf("%lf", &dataSet[inputCount]);
    }

    //Display menu
    printf("\nOptions:");
    printf("\n(1) Mean");
    printf("\n(2) Standard Deviation");
    printf("\n(3) Mode");
    printf("\n(4) Range");
    printf("\n(5) Restart/Exit");
    menuSelection = getMenuChoice(1,5,"\nSelection: ");

    //Perform operation
    switch(menuSelection) {
          case 1:
               printf("MEAN: %f", calcMean(dataSet, userN));
               break;
          case 2:
               printf("STANDARD DEVIATION: %f", calcStdDev(dataSet, userN));
               break;
          case 3:
               printf("MODE: ");
               calcMode(dataSet, userN);
               break;
          case 4:
               printf("RANGE: %f", calcRange(dataSet, userN));
               break;
          case 5:
               printf("RESTART/EXIT: ");
               break;
    }

    free(dataSet);
    getch();
}

double** create2dArray(int arrayWidth, int arrayHeight) {
    //Make 2D array
    double **array = malloc(arrayHeight*sizeof(double*));
    //Loop through each row of above and created 'zeroed' arrays for 'width'
    int i;
    for(i=0;i<arrayHeight;i++) {
         array[i] = calloc(arrayWidth, sizeof(double));
    }
    return array;
}

int getMenuChoice(int lowerBound, int upperBound, char prompt[]) {
    int input = lowerBound - 1;
    while(input == lowerBound - 1) {
         printf("%s", prompt);
         scanf("%d", &input);
         if(input < lowerBound || input > upperBound) {
               input = lowerBound - 1;
               printf("ERROR! Value is not between %d and %d.\n", lowerBound, upperBound);
         }
    }
    return input;
}

int compare_doubles(const void *a, const void *b) {
       const double *da = (const double *) a;
       const double *db = (const double *) b;
       return (*da > *db) - (*da < *db);
}

double calcMean(double* array, int size) {
       double mean = 0;
       int i;
       for(i = 0; i < size; i++)
             mean += array[i];
       mean = mean/size;
       return mean;
}

double calcStdDev(double* array, int size) {
       double mean = calcMean(array, size);
       double stdDev = 0;
       int i;
       for(i=0;i<size;i++)
             stdDev += (array[i]-mean)*(array[i]-mean);
       stdDev = stdDev/(size - 1);
       return stdDev;
}

double** calcMode(double* array, int size) {
       int modeArrayWidth = (size + 1)/2; //Abs. max width of mode array
       qsort(array, size, sizeof(double), compare_doubles); //Sort data
       double** modeInfo = create2dArray(modeArrayWidth, 2); //WHY U CRASH?!?!

       //Find mode(s)
       int i;
       static nextModeIndex = 0;
       for(i=0; i<modeArrayWidth; i++) {
                if(array[i] == array[i+1]) {
                            int checker;
                            int index = -1;
                            for(checker=0; checker<modeArrayWidth; checker++) {
                                  if(modeInfo[checker][0] == array[i]) {
                                       index = checker;
                                       checker = modeArrayWidth;
                                       printf("INME");
                                  }
                            }
                            if(index == -1) {
                                     printf("HI");
                                 modeInfo[nextModeIndex][0] = array[i];
                                 modeInfo[nextModeIndex][1] += 2.0;
                                 nextModeIndex++;
                            }
                            else {
                                 printf("HELLO");
                                 modeInfo[index][1] += 1.0;
                                 nextModeIndex = index + 1;
                            }
                }
       }
       for(i=0;i<modeArrayWidth;i++)
            printf("%f %f\n", modeInfo[i][0], modeInfo[i][1]);
       return modeInfo;
}

double calcRange(double* array, int size) {
       qsort(array, size, sizeof(double), compare_doubles);
       return array[size-1] - array[0];
}