Timus 1297. Palindrome

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题目：Palindrome

题意：给出一段字符串，求其字串中的最长的回文串、

解法：枚举回文串的中间点，再往两边搜索，时间为O（n^2)

#include <iostream>#include <string>using namespace std;char s[2000];int n = 0;int main() {    char c;    while ((c = getchar()) != EOF && c != '\n') {        s[++n] = c;    }    int ans = 0, l = 0;    for (int i = 1; i <= n; i++) {        int x = i, y = i, t = -1;        while (x > 0 && y <= n && s[x] == s[y]) {            t += 2;            if (t > ans) {                ans = t;                l = x;            }            x--; y++;        }        x = i; y = i+1; t = 0;        while (x > 0 && y <= n && s[x] == s[y]) {            t += 2;            if (t > ans) {                ans = t;                l = x;            }            x--; y++;        }    }    for (int i = l; i <= l+ans-1; i++) cout << s[i];    cout << endl;}

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