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

// Réalisation Pierre DELMER et Gauthier HUBERT
// Projet Langage C : Tableaux et Pointeurs
// Date : 21/03/2017


int main(int argc,char **argv)
{
    double answer;
    int i;
    srand(time(NULL));
    printf("|************************** Welcome to the exercise_2 ! *************************|\n");
    printf("|                                                                                |\n");
    printf("|                                                                                |\n");
    printf("|                                                                                |\n");
    printf("|In this program we will manipulate a dynamic array !                            |\n");
    printf("|Would you like to enter in the program ? Press [1/0] ( 1 -> Enter || 0 -> Quit) |\n");
    printf("|                                                                                |\n");
    printf("|                                                                                |\n");
    printf("|               /!\\ Any error will close the program /!\\                       |\n");
    printf("|                                                                                |\n");
    printf("|                                                                                |\n");
    printf("|********************************************************************************|\n\n");
    printf("Choice : ");
    scanf("%lf", &answer);
    while((int)answer<0 || (int)answer>1)
    while(answer==1){                           //ENTRY MENU
        double menuloop = 1;
        double answervalues,selectedvalue,sizeTab,answerminus,minusone,menuanswer;
        int sequency = 0;
        int errorSequency = 0;
        double sum = 0;
        double var1 = 0;
        double var2;
        int maxIndex,minIndex,maxSecondIndex,minSecondIndex,max,min;
        printf("\n\nPlease, select the size of the array you want :");
        do{
            scanf("%lf", &sizeTab);                 // MENU SELECTION VALUE
        }while(sizeTab<=0);
        printf("By default, the values of the array will be randomly selected between -32767 and 32767.\n\n");
        printf("If you want to change these values : press 1\n");
        printf("If you want to keep these values : press 0");
        printf("\nChoice : ");
        scanf("%lf",&answervalues);
            if(answervalues == 1){
                printf("Please select the max value : ");
                do{
                    scanf("%lf", &selectedvalue);
                    if(selectedvalue==0){
                        printf("Error, please enter a correct value : ");
                    }
                }while(selectedvalue==0);
                if(selectedvalue<0){
                    selectedvalue=(int)(selectedvalue*(-1));
                }
            }
            if(answervalues==0){
                selectedvalue=32767;
            }
        int array[(int)sizeTab];
        if(selectedvalue!=32767){
            for(i=0;i<sizeTab;i++){
                array[i]=rand()%(((int)selectedvalue*2)+1)-(int)selectedvalue;
            }
        }else{
            for(i=0;i<sizeTab;i++){
                array[i]=(rand()*2+1)-(int)selectedvalue;
        }
        }
        printf("The draw's end is -1. Would you like to enter a specific index in the array for this value or adding it randomly ? [1/0]");
            printf("Choice : ");
            scanf("%lf", &answerminus);
        while((int)answerminus<0 || (int)answerminus>1){
                printf("Error, enter a correct value : ");
            scanf("%lf", &answerminus);
        }
        if(answerminus==1){
            printf("Select the index you want for a specific -1 : ");
            printf("Choice : ");
            scanf("%lf",&minusone);
            while((int)minusone<0 || (int)minusone>(sizeTab-1)){
                scanf("%lf", &minusone);
            }
            array[(int)minusone]=-1;
        }else{
            i=rand()%(int)sizeTab;                      // RANDOM -1
            array[i]=-1;
        }

        for(i=0;i<sizeTab;i++){                         //CALCULATE THE SEQUENCY
            if(array[i]>=0){
                sequency++;
            }
            if(array[i]==(-1)){
                break;
            }
            if(array[i]<(-1)){
                errorSequency = 1;
                sequency=0;
                break;
            }
        }
        int sequencyArray[(int)sequency];
        if(errorSequency == 0 && sequency > 0){
            for(i=0;i<sequency;i++){
                sequencyArray[i]=array[i];
            }
        }                           // MENU OF THE PROGRAM
        while(menuloop==1){
        printf("\n\n\n********** Menu **********\n");
        printf("Select the option you want : \n\n");
        printf("1\\ Display the array\n\n");
        printf("2\\ Calculate the longest sequency\n\n");
        printf("3\\ Calculate the index of the highest element (Return -1 if the sequency is empty)\n\n");
        printf("4\\ Calculate the index of the lowest element (Return -1 if the sequency is empty)\n\n");
        printf("5\\ Calculate the index of the second highest element and of the second lowest element (Return -1 if the sequency is empty)\n\n");
        printf("6\\ Calculate the average of the array (Return 0 if the sequency is empty)\n\n");
        printf("7\\ Calculate the variance and the standard deviation (Return 0 if the array is sequency)\n\n");
        printf("8\\ Exit the menu");
        printf("\n\nChoice :");
        scanf("%lf",&menuanswer);
        while((int)menuanswer<0 || (int)menuanswer>8){
            printf("Error, please enter a correct value : ");
            scanf("%lf",&menuanswer);
        }
        switch((int)menuanswer){
            case 1:{                // DISPLAY THE ARRAY

                for(i=0;i<sizeTab;i++){
                    printf("| %d |",array[i]);
                    if(i%11==10){
                        printf("\n");
                    }
                }
                printf("\n\n");
                break;
            }
            case 2:{
                if(sequency>0 && errorSequency == 0){
                    printf("The longest sequency is : %d",sequency);            // DISPLAY THE LONGEST SEQUENCY
                }
                if(errorSequency==1){
                    printf("Error, negative number in the sequency");
                }
                if(sequency == 0 && errorSequency == 0){
                    printf("The sequency is empty");
                }
                break;
            }
            case 3:{                        // DISPLAY THE MAX INDEX
                max=sequencyArray[0];
                maxIndex=0;
                for(i=0;i<sequency;i++){
                    if(sequencyArray[i]>=max){
                        max=sequencyArray[i];
                        maxIndex=i;
                    }
                }
                if(sequency!=0){
                    printf("Index of the max element is : %d",maxIndex);
                }else{
                printf("Empty sequency, returning -1");
                }
                break;
            }
            case 4:{                    // DISPLAY THE MIN INDEX
                min=sequencyArray[0];
                minIndex=0;
                for(i=0;i<sequency;i++){
                    if(sequencyArray[i]<=min){
                        min=sequencyArray[i];
                        minIndex=i;
                    }
                }
                if(sequency!=0){
                    printf("Index of the min element is : %d",minIndex);
                }else{
                printf("Empty sequency, returning -1");
                }
                break;
            }
            case 5:{                        // DISPLAY SECOND MAX AND MIN
                if(sequency == 1){
                    printf("Sequency length is 1, no second element.");
                    break;
                }
                if(sequency == 0){
                    printf("\nEmpty sequency, returning -1");
                    break;
                }
                max=sequencyArray[0];
                maxIndex=0;
                for(i=0;i<sequency;i++){
                    if(sequencyArray[i]>=max){
                        max=sequencyArray[i];
                        maxSecondIndex = maxIndex;
                        maxIndex=i;
                    }
                }
                if(sequency!=0){
                    printf("Index of the second max element is : %d",maxSecondIndex);
                }
                min=sequencyArray[0];
                minIndex=0;
                for(i=0;i<sequency;i++){
                    if(sequencyArray[i]<=min){
                        min=sequencyArray[i];
                        minSecondIndex=minIndex;
                        minIndex=i;
                    }
                }
                if(sequency!=0){
                    printf("\nIndex of the second min element is : %d",minSecondIndex);
                }
                break;
            }
            case 6: {                   // DISPLAY THE AVERAGE
                if(sequency == 1){
                    printf("Sequency length is 1, the average is : %d",sequencyArray[0]);
                    break;
                }
                if(sequency == 0){
                    printf("\nEmpty sequency, the average is 0");
                    break;
                }
                for(i=0;i<sequency;i++){
                    sum = sum + sequencyArray[i];
                }
                sum = sum / i;
                printf("The average is : %lf",sum);
                break;
            }
            case 7:{                // DISPLAY THE VARIANCE AND THE STANDARD DEVIATION
                if(sequency == 1){
                    var1 = sequencyArray[0];
                    var1 = pow(var1,2);
                    var1 = (var1/1)-pow(sum,2);
                    var2 = sqrt(var2);
                    printf("The value of the variance is : %lf.2 and the standard deviation is : %lf",var1,var2);
                    break;
                }
                if(sequency == 0){
                    printf("\nEmpty sequency, returning 0");
                    break;
                }
                for(i=0;i<sequency;i++){
                    var1 = var1 + pow(sequencyArray[i],2);
                }
                var1 = var1 / i;
                var1 = var1 - pow(sum,2);
                var2 = sqrt(var1);
                printf("The value of the variance is : %lf.2 and the standard deviation is : %lf.2",var1,var2);
                break;
            }
            case 8:{            // QUITE MENU
                menuloop=0;
                break;
            }
        }
        }
    printf("\n\n\n********* Would you like to restart the program ? Press [1/0] *********\n\n");
    printf("/!\\ Any error will close the program /!\\ \n\n");
    printf("Choice : ");
    scanf("%lf",&answer);
    }

    return 0;
}