计算阶段油耗 和 总油耗

/* 计算油量、里程
输入每阶段的油量、历程，即时输出每阶段耗油量
推出时输出总耗油量 */
#include <stdio.h>

int main(){
    /*定义每阶段油耗、里程，总耗油，总里程*/
    float miles, gallons, sum_mailes = 0.00, sum_gallons = 0.00;
    /* 提示输入阶段耗油 */
    printf("Enter the gallons used: (-1 to end): ");
    /* 接收阶段耗油 */
    scanf("%f", &gallons);

    /* 如果阶段耗油不为-1，则进行循环 */
    while (-1 != gallons){
        /* 提示输入里程 */
        printf("Enter the miles driven: ");
        /* 接收里程 */
        scanf("%f", &miles);
        /* 把里程和油耗进行累计，为总里程、总油耗做准备 */
        sum_gallons = sum_gallons + gallons;
        sum_mailes = sum_mailes + miles;
        /* 输入本次耗油量 */
        printf("The miles / gallons for this tank was %.2f\n\n", miles/gallons);
        /* 再次提示输入阶段油耗 */
        printf("Enter the gallons used: (-1 to end): ");
        /* 接收阶段油耗 */
        scanf("%f", &gallons);
    }
    /* 退出循环后输出总油耗 */
    printf("The overall miles / gallons was %.2f", sum_mailes/sum_gallons);

    return 0;
}