View Compilation Error

0_0_39029991_2348.cpp:2:1: error: '_int64' does not name a type
    2 | _int64 minx(_int64  p1,_int64  p2,_int64  p3)
      | ^~~~~~
0_0_39029991_2348.cpp: In function 'int main()':
0_0_39029991_2348.cpp:11:4: error: '_int64' was not declared in this scope
   11 |    _int64  num[10000],min;
      |    ^~~~~~
0_0_39029991_2348.cpp:14:4: error: 'num' was not declared in this scope; did you mean 'enum'?
   14 |    num[0]=1;
      |    ^~~
      |    enum
0_0_39029991_2348.cpp:16:15: error: 'minx' was not declared in this scope
   16 |    {   num[i]=minx(p1*num[a],p2*num[b],p3*num[c]);  //状态转移方程
      |               ^~~~