请教 <C++程序设计语言题解> 第10章直方图习题的一个问题

lazywrite

#include <iostream> #include <cstdio> #include <cstddef> #include <cassert> using std::ostream; using std::cout; class Histogram {     public:         Histogram (ptrdiff_t minval, size_t gap, size_t nbins);         ~Histogram () { delete[] bin_; }         void record (ptrdiff_t);         void output_to (std::ostream&);     private:         ptrdiff_t const minval_,maxval_;         size_t const gap_;         size_t *const bin_;         size_t n_too_small_, n_too_large_; }; Histogram :: Histogram(ptrdiff_t m, size_t g, size_t n)     : minval_(m), maxval_(m+n*g-1), gap_(g),       bin_(new size_t[n]), n_too_small_(0), n_too_large_(0) {         assert(g != 0 && n != 0);       } void Histogram :: record (ptrdiff_t datapoint) {     if (datapoint < minval_)         ++n_too_small_;     else if (datapoint > maxval_)         ++n_too_large_;     else         ++bin_[(datapoint - minval_) / gap_]; } void Histogram :: output_to(std::ostream& output) {     output << "<" << minval_ << ":" << n_too_small_ << "n";     for (ptrdiff_t left = minval_; left < maxval_; left += gap_) {         output << left << ":" << bin_[(left-minval_)/gap_] << "n";     }     output << ">" << maxval_<<":" << n_too_large_<<"n"; } int main () {     Histogram h(1, 1, 10);     for (ptrdiff_t i = 0; i < 10; i ++) {         h.record(i);     }     h.output_to(cout);         return 0; }

这是《C++程序设计语言》那本习题题解书上的解答，别的其实不用看了，主要看那个output_to函数，编译一下，然后用valgrind查看运行，会有memory error，我不清楚标准库本来就这样，还是什么地方没用对，多谢。