题目:http://pat.zju.edu.cn/contests/pat-a-practise/1040
题解:
代码:
#include<cstdio> #include<cstring> #include<cmath> #include<string> #include<vector> #include<map> #include<set> #include<algorithm> using namespace std; int main() { char ch[1005]; gets(ch); int maxx=0,n=strlen(ch); for(int i=0;i<n;++i) { for(int j=0;i-j>=0&&i+j<n;++j) { if(ch[i-j]!=ch[i+j]) break; if(maxx<2*j+1) maxx=2*j+1; } for(int j=0;i-j>=0&&i+j<n;++j) { if(ch[i-j]!=ch[i+j+1]) break; if(maxx<2*j+2) maxx=2*j+2; } } printf("%d\n",maxx); return 0; }