[Usaco2017 Feb]Why Did the Cow Cross the RoadII
[题目链接]
https://www.lydsy.com/JudgeOnline/problem.php?id=4993
[算法]
动态规划
转移类似于求LCS
[代码]
#include<bits/stdc++.h> using namespace std; #define MAXN 1010 int n; int a[MAXN] , b[MAXN]; int f[MAXN][MAXN]; template <typename T> inline void chkmax(T &x,T y) { x = max(x,y); } template <typename T> inline void chkmin(T &x,T y) { x = min(x,y); } template <typename T> inline void read(T &x) { T f = 1; x = 0; char c = getchar(); for (; !isdigit(c); c = getchar()) if (c == '-') f = -f; for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - '0'; x *= f; } int main() { read(n); for (int i = 1; i <= n; i++) read(a[i]); for (int i = 1; i <= n; i++) read(b[i]); for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { if (abs(a[i] - b[j]) <= 4) f[i][j] = f[i - 1][j - 1] + 1; else f[i][j] = max(f[i][j - 1] , f[i - 1][j]); } } printf("%d\n",f[n][n]); return 0; }