View Compilation Error

0_0_18018997_25810.cpp:4:1: error: '_int64' does not name a type
 _int64 ans;
 ^
0_0_18018997_25810.cpp: In function 'void merge(int, int, int)':
0_0_18018997_25810.cpp:8:48: error: 'ans' was not declared in this scope
   if(sum[h2]>sum[h1]) tmp[tmp_num++]=sum[h1++],ans+=r-h2+1;//鑻ユ槸鍚庨潰鍒嗗壊鏁扮粍鐨刪2浣嶇疆鐨勬暟澶т簬鍓嶉潰h1浣嶇疆鐨勬暟璇存槑鏄搴忥紝鐢变簬鍚庨潰鐨勬暟缁勪负鏈夊簭鐨勶紝鎵�浠ュぇ浜巋2浣嶇疆鐨勬暟閮芥槸婊¤冻鏉′欢鐨�
                                                ^
0_0_18018997_25810.cpp: In function 'int main()':
0_0_18018997_25810.cpp:33:9: error: 'ans' was not declared in this scope
         ans=0;//ans涓哄叾鈥滄搴忓鈥濈殑涓暟
         ^