最长上升子序列（代码实现）

经典问题，不在赘述

#include <cstdio>#include <cstring>const int maxn = 10000;//用maxlen[i]表示a[1], a[2],..., a[k]中最长上升子序列的长度//那么状态转移方程为//maxlen[1] = 1//maxlen[i] = 1 + MAX{maxlen[j], 其中1 <= j < i, a[j] < a[i]}, (1 < i <= n)void init(int n, int *a, int *maxlen){    memset(maxlen, 0, sizeof(maxlen));maxlen[1] = 1;for (int i = 2; i <= n; i++) {int tem = 0;for (int j = 1; j < i; j++) {if (a[j] < a[i] && tem < maxlen[j])tem = maxlen[j];}maxlen[i] = tem + 1;}return;}//寻找maxlen[maxn]中的最大值int solve(int n, int *a, int *maxlen){int ans = 0;for (int i = 1; i <= n; i++)if (ans < maxlen[i])ans = maxlen[i];return ans;}int main(){    freopen("data.in", "r", stdin);int n;while (scanf("%d", &n) == 1) {int a[maxn], maxlen[maxn];for (int i = 1; i <= n; i++)scanf("%d", a + i);init(n, a, maxlen);int ans = solve(n, a, maxlen);printf("%d\n", ans);}return 0;}