View Compilation Error

0_0_22261001_18766.cpp:5:1: error: '_int64' does not name a type
 _int64 ans;
 ^
0_0_22261001_18766.cpp: In function 'void merge(int, int, int)':
0_0_22261001_18766.cpp:9:48: error: 'ans' was not declared in this scope
   if(sum[h2]>sum[h1]) tmp[tmp_num++]=sum[h1++],ans+=r-h2+1;//若是后面分割数组的h2位置的数大于前面h1位置的数说明是正序，由于后面的数组为有序的，所以大于h2位置的数都是满足条件?
                                                ^
0_0_22261001_18766.cpp: In function 'int main()':
0_0_22261001_18766.cpp:34:9: error: 'ans' was not declared in this scope
         ans=0;//ans为其“正序对”的个数
         ^