76. Construct UART Data Frame with Parity Bit

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

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

uint8_t create_uart_frame(uint8_t data, UART_Control *ctrl) {
    // Your logic here
    uint8_t frame = 0;
    if (ctrl->parity_enable == 0) {
        frame = data & 0x7F;
    } else {
        int parity_count = 0;
        for (uint8_t d = data; d > 0; d &= d - 1) {
            ++parity_count;
        }

        uint8_t parity_bit = ctrl->parity_type ^ (parity_count & 1);
        frame = (data & 0x7F) | (parity_bit << 7);
    }

    return frame;
}

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;
}