simple C 100%
\nint findComplement(int num){\n    int temp = num, c = 0;\n    while(temp>0)\n    {\n        c = (c<<1)|1;\n        temp >>= 1;\n    }  \n    return num ^ c;\n
```\nint findComplement(int num){\n    int temp = num, c = 0;\n    while(temp>0)\n    {\n        c = (c<<1)|1;\n        temp >>= 1;\n    }  \n    return num ^ c;\n}\n```
['C']