1078. 字符串压缩与解压 (20)

#include <iostream>
using namespace std;
int main() {
char t;
cin >> t;
getchar();
string s, num;
getline(cin, s);
int cnt = 1;
if (t == 'D') {
for (int i = 0; i < s.length(); i++) {
if (s[i] >= '0' && s[i] <= '9') {
num += s[i];
} else {
if (num.length() > 0) cnt = stoi(num);
while(cnt--) cout << s[i];
cnt = 1;
num = "";
}
}
} else if (s.length() != 0) {
char pre = s[0];
for (int i = 1; i < s.length(); i++) {
if (s[i] == pre) {
cnt++;
} else {
if (cnt >= 2) cout << cnt;
cout << pre;
cnt = 1;
pre = s[i];
}
}
if (cnt >= 2) cout << cnt;
cout << pre;
}
return 0;
}