P4888 三去矩阵
给出一个字符矩阵, 多次询问求以 \((x, y)\) 为中心的最长回文串长度(即横竖两种)
\(l, q <= 2000\)
Solution
数据范围小直接模拟即可
Code
#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>
#include<algorithm>
#include<climits>
#define LL long long
using namespace std;
int RD(){
int out = 0,flag = 1;char c = getchar();
while(c < '0' || c >'9'){if(c == '-')flag = -1;c = getchar();}
while(c >= '0' && c <= '9'){out = out * 10 + c - '0';c = getchar();}
return flag * out;
}
const int maxn = 4019;
int len, na;
char map[maxn][maxn];
int get_max(int x, int y){
int ans = -1, lenth = 1;
while(x + lenth <= len && x - lenth >= 1){
if(map[x + lenth][y] == map[x - lenth][y])lenth++;
else break;
}
ans = lenth, lenth = 1;
while(y + lenth <= len && y - lenth >= 1){
if(map[x][y + lenth] == map[x][y - lenth])lenth++;
else break;
}
ans = max(ans, lenth);
return 2 * ans - 1;
}
int main(){
len = RD(), na = RD();
for(int i = 1;i <= len;i++)for(int j = 1;j <= len;j++)cin>>map[i][j];
for(int i = 1;i <= na;i++){
int x = RD(), y = RD();
printf("%d\n", get_max(x, y));
}
return 0;
}
原文地址:https://www.cnblogs.com/Tony-Double-Sky/p/9693634.html
时间: 2024-10-12 03:32:11