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// C program for Highest Response Ratio Next (HRRN) Scheduling
#include <stdio.h>

// Defining process details
struct process {
char name;
int at, bt, ct, wt, tt;
int completed;
float ntt;
} p[10];

int n;

// Sorting Processes by Arrival Time
void sortByArrival()
{
struct process temp;
int i, j;

// Selection Sort applied
for (i = 0; i < n - 1; i++) {
for (j = i + 1; j < n; j++) {

// Check for lesser arrival time
if (p[i].at > p[j].at) {

// Swap earlier process to front
temp = p[i];
p[i] = p[j];
p[j] = temp;
}
}
}
}

void main()
{
int i, j, t, sum_bt = 0;
char c;
float avgwt = 0, avgtt = 0;
n = 5;

// predefined arrival times
int arriv[] = { 0, 2, 4, 6, 8 };

// predefined burst times
int burst[] = { 3, 6, 4, 5, 2 };

// Initializing the structure variables
for (i = 0, c = 'A'; i < n; i++, c++) {
p[i].name = c;
p[i].at = arriv[i];
p[i].bt = burst[i];

// Variable for Completion status
// Pending = 0
// Completed = 1
p[i].completed = 0;

// Variable for sum of all Burst Times
sum_bt += p[i].bt;
}

// Sorting the structure by arrival times
sortByArrival();
printf("nNametArrival TimetBurst TimetWaiting Time");
printf("tTurnAround Timet Normalized TT");
for (t = p[0].at; t < sum_bt;) {

// Set lower limit to response ratio
float hrr = -9999;

// Response Ratio Variable
float temp;

// Variable to store next processs selected
int loc;
for (i = 0; i < n; i++) {

// Checking if process has arrived and is Incomplete
if (p[i].at <= t && p[i].completed != 1) {

// Calculating Response Ratio
temp = (p[i].bt + (t - p[i].at)) / p[i].bt;

// Checking for Highest Response Ratio
if (hrr < temp) {

// Storing Response Ratio
hrr = temp;

// Storing Location
loc = i;
}
}
}

// Updating time value
t += p[loc].bt;

// Calculation of waiting time
p[loc].wt = t - p[loc].at - p[loc].bt;

// Calculation of Turn Around Time
p[loc].tt = t - p[loc].at;

// Sum Turn Around Time for average
avgtt += p[loc].tt;

// Calculation of Normalized Turn Around Time
p[loc].ntt = ((float)p[loc].tt / p[loc].bt);

// Updating Completion Status
p[loc].completed = 1;

// Sum Waiting Time for average
avgwt += p[loc].wt;
printf("n%ctt%dtt", p[loc].name, p[loc].at);
printf("%dtt%dtt", p[loc].bt, p[loc].wt);
printf("%dtt%f", p[loc].tt, p[loc].ntt);
}
printf("nAverage waiting time:%fn", avgwt / n);
printf("Average Turn Around time:%fn", avgtt / n);
}