Submission #231711

#	Time	Username	Problem	Language	Result	Execution time	Memory
231711		kshitij_sodani	Boat (APIO16_boat)	C++17	0 / 100	760 ms	9332 KiB

boat

#include <bits/stdc++.h>
#include <iostream>
using namespace std;
typedef int64_t llo;
#define mp make_pair
#define a first
#define b second
#define pb push_back
int n,aa,bb;
map<int,int> dd;
int si[2001];
llo mod=1000000007;
vector<int> cc;
vector<pair<int,int>> it;
int fac[501];
int fac2[501];
int pre[2001][501];
int pre2[2001][501];
int com[501][501];
int dp[501][2001];
int ind2=0;

int mod2(int ee,int ff){
	if(ff==0){
		return 1;
	}
	int ans=mod2(ee,ff/2);
	ans*=ans;
	ans%=mod;
	if(ff%2==1){
		ans*=ee;
		ans%=mod;
	}
	return ans;
}
void comp(){
	fac[0]=1;
	for(int i=1;i<501;i++){
		fac[i]=fac[i-1]*i;
		fac[i]%=mod;
	}
	for(int i=0;i<501;i++){
		fac2[i]=mod2(fac[i],mod-2);
	}
}
void ncr(){
	for(int i=1;i<n+1;i++){
		for(int j=0;j<=i;j++){
			com[i][j]=fac2[j]*fac2[i-j];
			com[i][j]%=mod;
			com[i][j]*=fac[i];
			com[i][j]%=mod;
		}
	}
}
void comp2(){
	fac[0]=1;
	for(int i=0;i<ind2;i++){
		int cur=1;
		pre[i][0]=0;
		for(int j=1;j<n+1;j++){
			if(j<=si[i]){
				cur*=mod2(j,mod-2);
				cur%=mod;
				cur*=(si[j]-j+1);
				cur%=mod;
				pre[i][j]=cur;
				pre[i][j]+=pre[i][j-1];
				pre[i][j]%=mod;
			}
			else{
				pre[i][j]=pre[i][j-1];
			}
		}		
	}
	for(int i=0;i<ind2;i++){
		for(int j=1;j<n+1;j++){
			pre2[i][j]=0;
			for(int k=1;k<=j;k++){
				pre2[i][j]+=pre[i][k]*com[j-1][k-1];
				pre2[i][j]%=mod;
			}
		}
	}
}

int main(){
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>aa>>bb;
		cc.pb(aa);
		cc.pb(bb);
		it.pb({aa,bb});
	}
	comp();//factorial
	ncr();//computing iCj for i and j from 1 to n
	sort(cc.begin(),cc.end());
	for(int i=0;i<cc.size();i++){
		if(i<cc.size()-1 and cc[i]==cc[i+1]){
			continue;
		}
		dd[cc[i]]=ind2;
		ind2+=1;
		si[dd[cc[i]]]=1;
		if(i<cc.size()-1){
			if(cc[i]<cc[i+1]+1){
				si[ind2]=cc[i+1]-cc[i]-1;
				ind2+=1;
			}
		}
	}
	comp2();
	for(int i=0;i<n;i++){
		it[i].a=dd[it[i].a];
		it[i].b=dd[it[i].b];
	}


	for(int i=0;i<n;i++){
		for(int j=0;j<cc.size();j++){
			dp[i][j]=0;
		}
	}
	for(int j=0;j<cc.size();j++){
		if(j>=it[0].a and j<=it[0].b){
			dp[0][j]=1;
		}
		if(j>0){
			dp[0][j]+=dp[0][j-1];
		}
	}
	for(int i=1;i<n;i++){
		for(int j=0;j<cc.size();j++){

		}
	}







	
	
	return 0;
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:98:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<cc.size();i++){
              ~^~~~~~~~~~
boat.cpp:99:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i<cc.size()-1 and cc[i]==cc[i+1]){
      ~^~~~~~~~~~~~
boat.cpp:105:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i<cc.size()-1){
      ~^~~~~~~~~~~~
boat.cpp:120:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<cc.size();j++){
               ~^~~~~~~~~~
boat.cpp:124:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int j=0;j<cc.size();j++){
              ~^~~~~~~~~~
boat.cpp:133:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<cc.size();j++){
               ~^~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42