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Commit 55d0e51

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Cacti problems
1 parent f254151 commit 55d0e51

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3 files changed

+271
-0
lines changed

3 files changed

+271
-0
lines changed

‎DMOJ/coci07c1p6.cpp

Lines changed: 135 additions & 0 deletions
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#include <bits/stdc++.h>
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using namespace std;
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const int MAXN = 2*1e4 + 10;
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vector<int> grafo[MAXN],tree[MAXN];
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deque<int> ciclo[MAXN];
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int cicloId,N,M,path[MAXN],tour[MAXN],dfs1Parent[MAXN],num[MAXN],low[MAXN],dfsCount;
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void dfs1(int v,int p){
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num[v] = ++dfsCount;
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low[v] = dfsCount;
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for(int u : grafo[v]){
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if(u == p) continue;
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if(num[u] == 0){
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dfs1Parent[u] = v;
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dfs1(u,v);
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if(num[v] < low[u]){
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tree[u].push_back(v);
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tree[v].push_back(u);
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}
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low[v] = min(low[v],low[u]);
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}
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else if(num[u] < num[v]){
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low[v] = min(low[v],num[u]);
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cicloId++;
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int k = v;
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while(k != u){
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ciclo[cicloId].push_back(k);
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k = dfs1Parent[k];
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}
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ciclo[cicloId].push_back(u);
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reverse(ciclo[cicloId].begin(),ciclo[cicloId].end());
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for(int k : ciclo[cicloId]){
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tree[k].push_back(cicloId);
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tree[cicloId].push_back(k);
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}
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}
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}
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}
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void dfs2(int v,int p){
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if(v <= N){
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tour[v] = 0;
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path[v] = 0;
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for(int u : tree[v]){
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if(u == p) continue;
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dfs2(u,v);
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if(u > N){
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tour[v] += (1 + tour[u]);
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}
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}
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for(int u : tree[v]){
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if(u == p) continue;
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if(u <= N){
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path[v] = max(path[v], tour[v] + path[u] + 1);
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}
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else{
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path[v] = max(path[v], tour[v] - (1 + tour[u]) + (1 + path[u]) );
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}
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}
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path[v] = max(path[v],tour[v]);
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}
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else{
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tour[v] = 0;
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path[v] = 0;
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while(ciclo[v].front() != p){
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ciclo[v].push_back(ciclo[v].front());
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ciclo[v].pop_front();
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}
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for(int u : ciclo[v]){
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if(u == p) continue;
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dfs2(u,v);
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tour[v] += (1 + tour[u]);
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}
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int pref = 0;
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for(int u : ciclo[v]){
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if(u == p) continue;
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path[v] = max(path[v], pref + path[u] );
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pref += (1 + tour[u]);
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}
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reverse(ciclo[v].begin(),ciclo[v].end());
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pref = 0;
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for(int u : ciclo[v]){
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if(u == p) continue;
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path[v] = max(path[v], pref + path[u] );
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pref += (1 + tour[u]);
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}
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path[v] = max(path[v],tour[v]);
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}
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}
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int main(){
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scanf("%d %d",&N,&M);
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cicloId = N;
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for(int i = 1;i<=M;i++){
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int u,v;
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scanf("%d %d",&u,&v);
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grafo[u].push_back(v);
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grafo[v].push_back(u);
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}
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dfs1(1,-1);
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dfs2(1,-1);
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//for(int i = 1;i<=cicloId;i++) printf("I %d P %d T %d\n",i,path[i],tour[i]);
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printf("%d\n",path[1]);
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return 0;
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}

‎DMOJ/si17c3p4.cpp

Lines changed: 66 additions & 0 deletions
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#include <bits/stdc++.h>
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using namespace std;
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typedef long long ll;
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const int MAXN = 2*1e4 + 10;
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const int MOD = 1e9 + 7;
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vector<int> grafo[MAXN];
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int num[MAXN],low[MAXN],dfsParent[MAXN],level[MAXN],dfsCount,went_up[MAXN],isCactus,N,M;
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ll ans;
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void dfs(int v,int p){
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if(!isCactus) return;
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num[v] = ++dfsCount;
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low[v] = num[v];
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for(int u : grafo[v]){
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if(u == p) continue;
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if(num[u] == 0){
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dfsParent[u] = v;
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level[u] = level[v] + 1;
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dfs(u,v);
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}
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else if(num[u] < num[v]){
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low[v] = min(low[v],num[u]);
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ans = (ans * (level[v] - level[u] + 1)) % MOD;
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int k = v;
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while(k != u){
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if(went_up[k]){
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isCactus = 0;
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break;
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}
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went_up[k] = 1;
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k = dfsParent[k];
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}
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}
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}
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}
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int main(){
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ans = 1;
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isCactus = 1;
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scanf("%d %d",&N,&M);
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for(int i = 1;i<=M;i++){
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int u,v;
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scanf("%d %d",&u,&v);
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grafo[u].push_back(v);
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grafo[v].push_back(u);
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}
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dfs(1,-1);
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for(int i = 2;i<=N;i++){
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if(num[i] == 0) isCactus = 0;
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}
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if(isCactus) printf("%lld\n",ans);
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else printf("safe\n");
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return 0;
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}

‎DMOJ/tle17c4p5.cpp

Lines changed: 70 additions & 0 deletions
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#include <bits/stdc++.h>
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using namespace std;
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typedef long long ll;
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const int MAXN = 200010;
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ll seg[4*MAXN],MOD;
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int maior_primo[MAXN],frequencia[MAXN],N;
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ll binary_expo(ll x,int y){
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ll ans = 1,sq = x;
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for(int i = 0;(1 << i) <= y;i++){
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if(y & (1 << i)) ans = (ans*sq) % MOD;
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sq = (sq*sq) % MOD;
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}
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return ans;
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}
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void update(int pos,int left,int right,int x){
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if(left == right){
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seg[pos] = binary_expo(x,frequencia[x]);
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return;
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}
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int mid = (left+right)/2;
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if(x <= mid) update(2*pos,left,mid,x);
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else update(2*pos+1,mid+1,right,x);
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seg[pos] = (seg[2*pos]*seg[2*pos+1]) % MOD;
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}
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void add(int x){
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while(x > 1){
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int y = maior_primo[x];
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frequencia[y]++;
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update(1,1,N,y);
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x /= y;
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}
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}
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void remove(int x){
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while(x > 1){
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int y = maior_primo[x];
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frequencia[y]--;
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update(1,1,N,y);
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x /= y;
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}
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}
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int main(){
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scanf("%d %lld",&N,&MOD);
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maior_primo[1] = 1;
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for(int i = 2;i <= N;i++){
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if(maior_primo[i] != 0) continue;
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for(int j = i;j<=N;j+=i) maior_primo[j] = i;
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}
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for(int i = 1;i<=4*N;i++) seg[i] = 1;
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printf("1\n");
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for(int i = N,j = 1;i>=1;i--,j++){
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add(i);
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remove(j);
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printf("%lld\n",seg[1]);
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}
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return 0;
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}

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