View Compilation Error

0_0_1115239_31423.cpp
0_0_1115239_31423.cpp(17) : error C2668: “abs” : 对重载函数的调用不明确
        VC\include\math.h(584): 可能是“long double abs(long double)”
        VC\include\math.h(536): 或       “float abs(float)”
        VC\include\math.h(530): 或       “double abs(double)”
        VC\include\math.h(528): 或       “long abs(long)”
        VC\include\stdlib.h(265): 或       “int abs(int)”
        试图匹配参数列表“(std::basic_string<_Elem,_Traits,_Ax>::size_type)”时
        with
        [
            _Elem=char,
            _Traits=std::char_traits<char>,
            _Ax=std::allocator<char>
        ]