C++ itoa注意地方

timer tm;
map<date, vector<PERSON> *> mpList;
date dtStartDate = from_undelimited_string("20021212");
//cout << to_iso_string(dtStartDate.end_of_month()) << endl;
date dtEndDate = from_undelimited_string("20131215");
int ndtEarlyYear = 0 ; // 记录dtEarly日期的年份
int ndtNearYear = 0; // 记录dtNear日期的年份
ndtEarlyYear = dtStartDate.year();
ndtNearYear = dtEndDate.year();
int nTemYear = 0;

char sz[20] = {'\0'};
string strYear = "";
strYear += sz;
date dtYear;
for (nTemYear = ndtEarlyYear; nTemYear <= ndtNearYear; ++nTemYear)
{
itoa(nTemYear,sz,10); //注意这里如果sz字符数组的长度小于nTemYear的字符数会出现意外的情况

strYear = sz;
strYear.append("1231");

dtYear = from_undelimited_string(strYear);
cout << to_iso_string(dtYear);

}