CF1427 C.The Hard Work of Paparazzi【LIS】

题目链接：codeforces1427C The Hard Work of Paparazzi

题解

直接 枚举。观察 比较小，当 时，不用从头扫一遍，只要从 开始即可，用一个数组维护前 个的最大值。

参考代码

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#include <iostream>
#include <cstring>
using namespace std;
const int N = 1e5 + 10;
int r, n;
int t[N], x[N], y[N];
int dp[N], tmp[N];
int main() {
    cin >> r >> n;
    for (int i = 1; i <= n; i++) {
        cin >> t[i] >> x[i] >> y[i];
    }
    memset(dp, -0x3f, sizeof(dp));
    dp[0] = 0;
    x[0] = y[0] = 1;
    for (int i = 1; i <= n; i++) {
        if (i >= r*2) dp[i] = max(dp[i], tmp[i-2*r] + 1);
        for (int j = max(0, i - 2*r); j <= i-1; j++) {
            if (abs(x[i] - x[j]) + abs(y[i] - y[j]) <= t[i] - t[j]) {
                dp[i] = max(dp[i], dp[j] + 1);
            }
        }
        tmp[i] = max(tmp[i-1], dp[i]);
    }
 	int ans = 0;
    for (int i = 1; i <= n; i++) {
        ans = max(ans, dp[i]);
    }
    cout << ans << endl;
    return 0;
}