View Compilation Error

0_0_22149769_4951.cpp:6:1: error: '__int64_t' does not name a type
 __int64_t min(__int64_t a,__int64_t b){
 ^
0_0_22149769_4951.cpp: In function 'int main()':
0_0_22149769_4951.cpp:15:9: error: '__int64_t' was not declared in this scope
         __int64_t sum=0;
         ^
0_0_22149769_4951.cpp:20:9: error: 'sum' was not declared in this scope
         sum+=a*2+b;//刚开时必须去上海花费a工资b，最后一次必须回北京花费a
         ^
0_0_22149769_4951.cpp:22:23: error: expected ';' before 'x'
             __int64_t x,y;
                       ^
0_0_22149769_4951.cpp:23:13: error: 'x' was not declared in this scope
             x=(s[i]-s[i-1])*b;//上次不用回去，只需加上延误的时间
             ^
0_0_22149769_4951.cpp:24:13: error: 'y' was not declared in this scope
             y=2*a+b; //表示上次回去，所以先加上回去的费用a
             ^