Circular Buffer Read

Code

#include <stdio.h>
#include <stdint.h>

typedef struct {
    int buffer[100];   // Fixed memory for data
    int head;          // Write index
    int tail;          // Read index (not used here)
    int count;         // Number of elements in buffer
    int capacity;      // Maximum number of elements buffer can hold
} CircularBuffer;

void read_bytes(CircularBuffer *cb, int n){
    for(int i = 0; i < n; i++){
       if(cb->count > 0){
            // Read and print n values from the buffer
            printf("%d", cb->buffer[cb->tail]); 

            // Advance the tail properly with wrap-around
            cb->tail = (cb->tail + 1) % cb->capacity;
            // Decrease count after each successful read
            cb->count--;
       }
       else{
        printf("NULL");
       }
       // chỉ in space nếu chưa phải phần tử cuối
       if(i < n - 1) printf(" ");
    }
    printf("\nTail: %d", cb->tail);
}

int main(){
    CircularBuffer cb = {
        .buffer = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100},
        .head = 3,
        .tail = 7,
        .count = 6,
        .capacity = 10
    };

    int n;
    scanf("%d", &n);
    read_bytes(&cb, n);
    return 0;
}

Solving Approach