Merge pull request #606 from madihamallick/master

Added Job Sequencing Problem in C

Author: smv1999

Dynamic Programming/job_sequencing_greedyMethod.c

@@ -0,0 +1,122 @@
+/*Write a program to implement the job sequencing with  deadline problem using greedy method. Consider the  
+following data for the problem. N=4 
+
+    JOB:        J1   J2   J3   J4
+    PROFIT:     100  10   15   27
+    DEADLINE:    2    1   2     1
+*/
+
+#include <stdio.h>
+
+// Structure of each job
+struct job
+{
+    int id;
+    int profit;
+    int deadline;
+};
+
+/* Auxiliary Functions */
+
+int scanJobs(struct job Jobs[], int n)
+{
+    // Scan n number of jobs
+    int i, max_deadline = 0;
+    for (i = 0; i < n; i++)
+    {
+        printf("Enter the profit and deadline of job (J%d): ", i + 1);
+        scanf("%d %d", &Jobs[i].profit, &Jobs[i].deadline);
+        Jobs[i].id = i + 1;
+        if (Jobs[i].deadline > max_deadline)
+        {
+            max_deadline = Jobs[i].deadline;
+        }
+    }
+    return max_deadline;
+}
+
+void sort(struct job Jobs[], int n)
+{
+    // Sort the job in descending order of profit
+    int i, j;
+    struct job key;
+    for (i = 1; i < n; i++)
+    {
+        key = Jobs[i];
+        j = i - 1;
+        while ((j >= 0) && (Jobs[j].profit < key.profit))
+        {
+            Jobs[j + 1] = Jobs[j];
+            j--;
+        }
+        Jobs[j + 1] = key;
+    }
+}
+
+int isEmpty(int arr[], int i)
+{
+    // Returns True if i'th slot of an array is empty
+    return arr[i] == 0 ? 1 : 0;
+}
+
+void initSlots(int arr[], int m)
+{
+    // Initialise job slots to 0
+    int i;
+    for (i = 0; i < m; i++)
+    {
+        arr[i] = 0;
+    }
+}
+
+int job_sequencing(struct job Jobs[], int m)
+{
+    // Job sequencing function
+    int slots[m], profit = 0;
+    initSlots(slots, m);
+    int i, j, deadlineIdx;
+    for (i = 0; i < m; i++)
+    {
+        deadlineIdx = Jobs[i].deadline - 1;
+        if (isEmpty(slots, deadlineIdx))
+        {
+            slots[deadlineIdx] = Jobs[i].id;
+            profit += Jobs[i].profit;
+        }
+        else
+        {
+            for (j = deadlineIdx - 1; j >= 0; j--)
+            {
+                if (isEmpty(slots, j))
+                {
+                    slots[j] = Jobs[i].id;
+                    profit += Jobs[i].profit;
+                }
+            }
+        }
+    }
+    printf("\nJobs sequence: { ");
+    for (i = 0; i < m; i++)
+    {
+        printf("J%d ", slots[i]);
+    }
+    printf("}");
+    return profit;
+}
+
+int main()
+{
+    int n, m, max_profit;
+    /* 
+        n: number of jobs
+        m: number of job slots
+    */
+    printf("Enter the number of jobs: ");
+    scanf("%d", &n);
+    struct job Jobs[n];
+    m = scanJobs(Jobs, n);
+    sort(Jobs, n);
+    max_profit = job_sequencing(Jobs, m);
+    printf("\nOptimal maximum profit: %d\n", max_profit);
+    return 0;
+}