Construct UART Data Frame with Parity Bit

Code

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

typedef struct {
    uint8_t parity_enable : 1;
    uint8_t parity_type   : 1;
    uint8_t reserved      : 6;
} UART_Control;

int countones(uint8_t data){
    int parity=0;
    while(data>0){
        parity^=(data&1);
        data>>=1;
    }
    return parity;
}

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    // Your logic here

    int parity=0;
    if (ctrl->parity_enable==0){
        return data;
    }

    int ones=countones(data);
    int parbit;
    if (ctrl->parity_type==0){
        parbit=ones?1:0;
    } else {
        parbit=ones?0:1;
    }

    return (parbit<<7)|data;
}

int main() {
    uint8_t data;
    scanf("%hhu", &data);  // 7-bit input

    uint8_t parity_enable, parity_type;
    scanf("%hhu %hhu", &parity_enable, &parity_type);

    UART_Control ctrl;
    ctrl.parity_enable = parity_enable;
    ctrl.parity_type = parity_type;

    uint8_t frame = create_uart_frame(data, &ctrl);
    printf("frame = 0x%02X", frame);

    return 0;
}

Solving Approach