请指教 为什么 输出价格为0
# include<stdio.h> int taixfee(int clock,int miles) { float total,cost; if(clock>=5 && clock<23) { if(miles<=3) cost=0; else cost=(miles-3)*2.3; } else { if(miles<=3) cost=0; else cost=(miles-3)*2.3*1.2; } total =cost +14; return total; } main() { printf("费用为%.1f",taixfee(9,12)+taixfee(18,12)); }