#include<bits/stdc++.h>
using namespace std;
int p1,p2,p3;
string s1,s2;
int st;
int main()
{
	cin>>p1>>p2>>p3;
	cin>>s1;
	for(int i=1;i<s1.size()-1;i++){//排除第一个和最后一个的位置，防止访问越界
		if(s1[i]=='-'){
			int a=s1[i-1], b=s1[i+1];
			if(b>a){
				if((a>=97&&a<=122&&b<=122&&b>=97)||(b<=57&&b>=48&&a>=48&&a<=57)){//同数或同字母
				s2.clear(); st=b-a;
				if(st==1){
					s1.replace(i,1,"");
					continue;
				}
					//需注意，只有字母才能被大小写函数置换，数字不会受到影响
				if(p1==1){for(int j=1;j<st;j++){ s2+=string(p2,tolower(a+j));}}
				if(p1==2){for(int j=1;j<st;j++){ s2+=string(p2,toupper(a+j));}}
				if(p1==3){ for(int j=1;j<st;j++){ s2+=string(p2,'*'); } }
				if (p3 == 2) reverse(s2.begin(), s2.end());
				s1.replace(i,1,s2);//替换
				}
			}
		}
	}
	cout<<s1;
	return 0;
}

字符串模拟

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 1;
int p1, p2, p3;
string str, ans;
int main() {
  cin >> p1 >> p2 >> p3 >> str;
  for (int i = 0; i < str.size(); i++) {
    if (str[i] == '-' && i > 0 && i + 1 < str.size() && str[i - 1] < str[i + 1]) {
      char a = str[i - 1], b = str[i + 1];
      if (isdigit(a) && isdigit(b) || isalpha(a) && isalpha(b)) {
        if (a + 1 < b) {
          string tem;
          for (int c = a + 1; c < b; c++) {
            if (p1 == 1) tem += string(p2, tolower(c));
            if (p1 == 2) tem += string(p2, toupper(c));
            if (p1 == 3) tem += string(p2, '*');
          }
          if (p3 == 2) reverse(tem.begin(), tem.end());
          ans += tem;
        }
      } else ans += str[i];
    } else ans += str[i];
  }
  cout << ans;
  return 0;
}