bzoj 1193

大范围贪心， 小范围暴力。。。。。

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define pii pair<int,int>
#define piii pair<int, pair<int,int>>


using namespace std;

const int N=20+7;
const int M=1e4+7;
const int inf=0x3f3f3f3f;
const LL INF=0x3f3f3f3f3f3f3f3f;
const int mod=1e9 + 7;

int n, xp, yp, xs, ys, dx[] = {1, 1, 2, 2, -1, -1, -2, -2}, dy[] = {2, -2, 1, -1, 2, -2, 1, -1}, d[100][100];
bool check(int x, int y) {
    if(x < 0 || x >= 30) return false;
    if(y < 0 || y >= 30) return false;
    if(d[x][y] != inf) return false;
    return true;
}

void bfs() {
    queue<pii> que;
    que.push(mk(1, 1));
    d[1][1] = 0;
    while(!que.empty()) {
        pii u = que.front(); que.pop();
        for(int i = 0; i < 8; i++) {
            pii v = mk(u.fi + dx[i], u.se + dy[i]);
            if(check(v.fi, v.se)) {
                d[v.fi][v.se] = d[u.fi][u.se] + 1;
                que.push(v);
            }
        }
    }
}

int main() {
    memset(d, inf, sizeof(d));
    scanf("%d%d%d%d", &xp, &yp, &xs, &ys);
    int x = abs(xp - xs);
    int y = abs(yp - ys);
    int ans = 0;
    bfs();
    while(x >= 20 || y >= 20) {
        if(x < y) swap(x, y);
        x -= 2, y -= 1;
        x = abs(x), y = abs(y);
        ans++;
    }
    printf("%d
", ans + d[x + 1][y + 1]);
    return 0;
}
/*
*/