A.Intelligent Warehouse
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int maxn = 10000010;
int a[maxn], b[maxn], N;
typedef long long ll;
int ans;
int main(){
scanf("%d", &N);
for(int i = 0; i < N; i++){
int x;
scanf("%d", &x);
++a[x];
}
for(int i = 2; i <= 10000000; i++){
if(!a[i]) continue;
b[i] += a[i];
for(int j = 2; (ll)i * j <= 10000000; j++){
b[i * j] = max(b[i * j], b[i]);
}
ans = max(ans, b[i]);
}
printf("%d\n", ans + a[1]);
return 0;
}
J.Matrix Subtraction
- 二维树状数组可以写。这里就是用树状数组写的。
- 二位差分也可以写。在循环的时候求前缀和就行。
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 1010;
typedef long long ll;
int N, M, A, B;
ll tr[maxn][maxn];
int lowbit(int x){
return x & -x;
}
void add(int x, int y, ll val){
for(int i = x; i <= N; i += lowbit(i)){
for(int j = y; j <= M; j += lowbit(j)){
tr[i][j] += val;
}
}
}
ll query(int x, int y){
ll res = 0;
for(int i = x; i; i -= lowbit(i)){
for(int j = y; j; j -= lowbit(j)){
res += tr[i][j];
}
}
return res;
}
void insert(int x1, int y1, int x2, int y2, ll val) {
add(x1, y1, val);
add(x1, y2 + 1, -val);
add(x2 + 1, y1, -val);
add(x2 + 1, y2 + 1, val);
}
int main(){
int T;
scanf("%d", &T);
while(T--){
memset(tr, 0, sizeof tr);
scanf("%d%d%d%d", &N, &M, &A, &B);
for(int i = 1; i <= N; i++){
for(int j = 1; j <= M; j++){
ll x;
scanf("%lld", &x);
insert(i, j, i, j, x);
}
}
bool flag = true;
for(int i = 1; i <= N; i++){
for(int j = 1; j <= M; j++){
ll tmp = query(i, j);
if(tmp < 0){
flag = false;
break;
}
if(i + A - 1 > N || j + B - 1 > M) continue;
insert(i, j, i + A - 1, j + B - 1, -tmp);
}
if(!flag) break;
}
for (int i = 1; i <= N; i++) {
if (!flag) break;
for (int j = 1; j <= M; j++) {
ll tmp = query(i, j);
if (tmp) flag = false;
}
}
if(flag) printf("^_^\n");
else printf("QAQ\n");
}
return 0;
}