LIS 最长有序子序列（递增/递减/非递增/非递减）

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/*==================================================*\
| 最长有序子序列（递增/递减/非递增/非递减）
\*==================================================*/
const int N = 1001;
int a[N], f[N], d[N]; // d[i]用于记录a[0...i]的最大长度
int bsearch(const int *f, int size, const int &a) {
    int l=0, r=size-1;
    while( l <= r ){
        int mid = (l+r)/2;
        if( a > f[mid-1] && a <= f[mid] ) return mid;// >&&<= 换为: >= && <
        else if( a < f[mid] ) r = mid-1;
        else l = mid+1;
    }
}
int LIS(const int *a, const int &n){
    int i, j, size = 1;
    f[0] = a[0]; d[0] = 1;
    for( i=1; i < n; ++i ){
        if( a[i] <= f[0] ) j = 0; // <= 换为: <
        else if( a[i] > f[size-1] ) j = size++;// > 换为: >=
        else j = bsearch(f, size, a[i]);
        f[j] = a[i]; d[i] = j+1;
    }
    return size;
}
int main(void){
    int i, n;
    while( scanf("%d",&n) != EOF ){
        for( i=0; i < n; ++i ) scanf("%d", &a[i]);
printf("%d\n", LIS(a, n)); // 求最大递增/上升子序列(如果为最大非降子序列,只需把上面的注释部分给与替换)
    }
    return 0;
}

 

转载于:https://www.cnblogs.com/zhang1107/archive/2013/03/24/2979421.html