programs 1 to 6

prog1/prog1.c

@@ -0,0 +1,123 @@
+#include <stdio.h>
+
+typedef struct{
+    int SRN;
+    char name[50];
+    float marks;
+}Student;
+
+void storeRecords(int n);
+void mthRecord(int m);
+void deleteRecord(int SRN);
+
+int main() {
+    int n, m, SRN;
+
+    printf("Enter number of records:\n");
+    scanf("%d", &n);
+
+    storeRecords(n);
+
+    printf("\nEnter mth record to display:\n");
+    scanf("%d", &m);
+
+    mthRecord(m);
+
+    printf("\nEnter SRN to delete:");
+    scanf("%d", &SRN);
+
+    deleteRecord(SRN);
+    return 0;
+}
+
+void storeRecords(int n){
+    FILE* fp;
+    Student s;
+    fp = fopen("recoders.bin", "wb");
+
+    if(fp == NULL){
+        printf("Error opening file\n");
+        return;
+    }
+
+    for(int i = 0; i<n; i++){
+        printf("Students Record:%d\n", i+1);
+
+        printf("SRN: ");
+        scanf("%d", &s.SRN);
+
+        printf("Name: ");
+        scanf("%s", s.name);
+
+        printf("Marks: ");
+        scanf("%f", &s.marks);
+
+        fwrite(&s, sizeof(s), 1, fp);
+    }
+
+    fclose(fp);
+
+    printf("Records Stored successfully\n");
+
+}
+
+void mthRecord(int m){
+    FILE *fp;
+    Student s;
+
+    fp = fopen("recoders.bin", "rb");
+
+    if(fp == NULL){
+        printf("Error opening file\n");
+        return;
+    }
+
+    fseek(fp, (m-1)*sizeof(Student), SEEK_SET);
+
+    if(fread(&s, sizeof(Student), 1, fp) == 1){
+        printf("SRN: %d\n",  s.SRN);
+        printf("Name: %s\n", s.name);
+        printf("Marks: %.2f", s.marks);
+    }else{
+        printf("Record not found");
+    }
+
+    fclose(fp);
+
+}
+
+
+void deleteRecord(int SRN){
+    FILE *fp, *temp;
+    Student s;
+
+    int found = 0;
+
+    fp = fopen("recoders.bin", "rb");
+    temp = fopen("temp.bin", "wb");
+    if(fp == NULL || temp == NULL){
+        printf("Error opening file\n");
+        return;
+    }
+
+    while(fread(&s, sizeof(Student), 1, fp)){
+        if(s.SRN == SRN){
+            found = 1;
+            continue;
+        }
+        fwrite(&s, sizeof(Student), 1, temp);
+    }
+
+    fclose(fp);
+    fclose(temp);
+
+    remove("records.bin");
+    rename("temp.bin", "records.bin");
+
+    if(found){
+        printf("Record deleted successfully\n");
+    }else{
+        printf("Record not found\n");
+    }
+}
+

prog2/prog2.c

@@ -0,0 +1,117 @@
+#include <stdio.h>
+
+typedef struct{
+    int SRN;
+    char name[50];
+    float marks;
+}Student;
+
+void records(Student s[], int n);
+int createseekpositions(int pos[], int maxrecords);
+void displayrecords(int position);
+
+int main() {
+    int n, choice;
+    int positions[100];
+
+    printf("Enter number of records:");
+    scanf("%d", &n);
+
+    Student s[n];
+
+    for(int i=0; i<n; i++){
+        printf("Enter details of the student: %d\n", i+1);
+
+        printf("Enter SRN:");
+        scanf("%d", &s[i].SRN);
+
+        printf("Enter Name:");
+        scanf("%s", s[i].name);
+
+        printf("Enter marks:");
+        scanf("%f", &s[i].marks);
+    }
+
+    records(s, n);
+    int total = createseekpositions(positions, 100);
+
+    printf("\nSeek positions:\n");
+
+    for(int i=0; i<n; i++){
+        printf("Record %d starts at position %d\n", i+1, positions[i]);
+    }
+
+    printf("\nEnter record number to display: ");
+    scanf("%d", &choice);
+
+    if(choice >= 1 && choice <= total){
+        displayrecords(positions[choice - 1]);
+    }else{
+        printf("\nInvalid record number");
+    }
+    return 0;
+}
+
+void records(Student s[], int n){
+    FILE *fp;
+    fp = fopen("records.txt", "w");
+
+    if(fp == NULL){
+        printf("Error opening file\n");
+        return;
+    }
+
+    for(int i=0; i<n; i++){
+        fprintf(fp, "%d %s %.2f\n", s[i].SRN, s[i].name, s[i].marks);
+    }
+
+    fclose(fp);
+    printf("Records stored successfully");
+}
+
+int createseekpositions(int pos[], int maxrecords){
+    FILE *fp;
+    int count = 0;
+    Student temp;
+
+    fp = fopen("records.txt", "r");
+
+    if(fp == NULL){
+        printf("Error opening file\n");
+        return 0;
+    }
+
+    while(!feof(fp) && count < maxrecords){
+        pos[count] = ftell(fp);
+        if(fscanf(fp, "%d %S %f", &temp.SRN, temp.name, &temp.marks) == 3){
+            count++;
+        }
+
+    }
+    fclose(fp);
+    return count;
+}
+
+void displayrecords(int position){
+    FILE *fp;
+    Student s;
+    fp = fopen("records.txt", "r");
+
+    if(fp == NULL){
+        printf("Error opening file\n");
+        return;
+    }
+
+    fseek(fp, position, SEEK_SET);
+
+    if(fscanf(fp, "%d %s %f", &s.SRN, s.name, &s.marks) == 3){
+        printf("SRN: %d\n", s.SRN);
+        printf("Name: %s\n", s.name);
+        printf("Marks: %.2f\n", s.marks);
+    }else{
+        printf("Record not found\n");
+    }
+
+    fclose(fp);
+}
+

prog2/records.txt

@@ -0,0 +1,3 @@
+1 a 30.00
+2 b 60.00
+3 c 90.00

prog3/prog3.c

@@ -0,0 +1,41 @@
+#include <stdio.h>
+
+void printbits(int num);
+int countsetbits(int num);
+
+
+int main() {
+    int n;
+    printf("Enter an integer: ");
+    scanf("%d", &n);
+
+    printf("\nBinary Representation: ");
+    printbits(n);
+
+    printf("\nNumber of 1 bits = %d\n", countsetbits(n));
+
+    return 0;
+}
+
+void printbits(int num){
+    int totalbits = sizeof(int) * 8;
+    for(int i=totalbits -1; i>=0; i--){
+        int bit = (num >> i)&1;
+        printf("%d", bit);
+
+    }
+    printf("\n");
+}
+
+int countsetbits(int num){
+    int count = 0;
+    while(num!=0){
+        if((num&1)==1)
+            count++;
+
+            num = num>>1;
+    }
+
+
+    return count;
+}

prog4/prog4.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+struct Bitfield{
+    unsigned int firstbit:1;
+    unsigned int secondbit:2;
+    unsigned int thirdbit:3;
+};
+
+int main() {
+    struct Bitfield a;
+
+    a.firstbit = 1;
+    a.secondbit = 2;
+    a.thirdbit = 3;
+
+    printf("firstbit:%u\n", a.firstbit);
+    printf("secondbit:%u\n", a.secondbit);
+    printf("thirdbit:%u\n", a.thirdbit);
+
+    a.firstbit = 3;
+
+    printf("\nAfter Assigning 3 to firstbit: \n");
+    printf("firstbit = %u\n", a.firstbit);
+    return 0;
+}