题解 | 字符串展开

#include<bits/stdc++.h>
using namespace std;

bool sametype(char a,char b){
	return (isdigit(a) && isdigit(b) || islower(a) && islower(b));
}
int main(){
	int p1,p2,p3;  cin >> p1 >> p2 >> p3;
	string s;  cin  >> s;
	int n = s.size();
	for(int i=0 ; i <= n-1 ; i++){
		
		//需要操作 
		if(i > 0 && i < n-1 && s[i] == '-'){
			char left = s[i-1],right = s[i+1];
			
			if(sametype(left,right) && left < right){
				if(right == left + 1) //直接删除'-' 
				continue;
				
				string fill;
				//展开字符 
				for(char c = left + 1 ; c < right ; c++){
					char t = c;
					
					//p1
					if(p1 == 1){
						if(isalpha(c))
					    t = tolower(c);
					    
					}
					else if(p1 == 2){
						if(isalpha(c))
						t = toupper(c);
					}
					else if(p1 == 3)  //只有这条对数字有用 
					t = '*';
					
					//p2 
					for(int k=0 ; k < p2 ; k++){
						fill += t;
					}
				}	
				
				//p3
				if(p3 == 2){
					reverse(fill.begin(),fill.end());
				}
				cout << fill;
				continue;  //展开、输出原字符选一个进行 
			}
		}
		cout << s[i];
	
	}
    return 0;
}