蓝桥杯备考：模拟算法之字符串展开

P1098 [NOIP 2007 提高组] 字符串的展开 - 洛谷 | 计算机科学教育新生态

#include <iostream>
#include <cctype>
#include <algorithm>
using namespace std;
int p1,p2,p3;
string s,ret;
void add(char left,char right)
{string tmp;for(char ch = left+1;ch<right;ch++){char t = ch;if(p1==2&&isalpha(ch)) t=toupper(t);else if(p1==3) t='*';for(int i = 0;i<p2;i++){tmp+=t;}}if(p3 == 2) reverse(tmp.begin(),tmp.end());ret+=tmp;
}
int main()
{cin >> p1 >> p2 >> p3;cin >> s;int n = s.size();for(int i = 0;i<n;i++){char ch = s[i];if(ch != '-' || i==n-1 || i==0) ret+=ch;else{char left = s[i-1];char right = s[i+1];if((isdigit(left)&&isdigit(right)&&right>left)||(isalpha(left)&&isalpha(right) && right>left)){add(left,right);}else ret+=ch;} }cout << ret << endl;return 0;
}