最长上升子序列 董晓

include

include

include

using namespace std;

const int N=100010;
int n, a[N];
int len, b[N]; //记录上升子序列

int main(){
scanf("%d", &n);
for(int i=0; i<n; i++) scanf("%d", &a[i]);

b[0]=-2e9; //哨兵
for(int i=0; i<n; i++)
if(b[len]<a[i]) b[++len]=a[i]; //新数大于队尾数，则插入队尾
else *lower_bound(b,b+len,a[i])=a[i]; //替换第一个大于等于a[i]的数(贪心)

printf("%d\n", len);
}

include

include

include

using namespace std;

const int N=100010;
int n, a[N];
int len, b[N];

int find(int x){
int l=-1, r=len;
while(l+1<r){
int mid=l+r>>1;
if(b[mid]>=x) r=mid;
else l=mid;
}
return r;
}
int main(){
scanf("%d", &n);
for(int i=0; i<n; i++) scanf("%d", &a[i]);

b[0]=-2e9;
for(int i=0; i<n; i++){
if(b[len]<a[i]) b[++len]=a[i];
else b[find(a[i])]=a[i];
}

printf("%d\n", len);
}