zoj 3818 Pretty Poem

//AC#include <cstdio>#include <iostream>#include <cstring>#include <string>#include <algorithm>using namespace std;char ch[55];string str;int len;void work(){    for(int i=1; 3*i+2<=len; i++){        if((len-3*i) % 2 != 0) continue;        int j = (len-3*i)/2;        string A = str.substr(0, i);        string B = str.substr(i, j);        if(A == B) continue;        if(A + B + A + B + A == str){            puts("Yes"); return;        }    }    for(int i=1; 3*i+4<=len; i++){        for(int j=1; 3*(i+j)+1<=len; j++){            int k = len - 3*(i+j);            string A = str.substr(0, i);            string B = str.substr(i, j);            string AB = A + B;            string C = str.substr(2*(i+j), len-3*(i+j));            if(A == B || B == C || C == A) continue;            if(AB + AB + C + AB == str){                puts("Yes"); return;            }        }    }    puts("No");}int main() {int t;scanf("%d", &t);while (t--) {str.clear();scanf("%s", ch);len = strlen(ch);for (int i = 0; i < len; i++)if (isalpha(ch[i]))str += ch[i];len = str.length();        work();}return 0;}