#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pair<int,int>> vpi;
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)
#define pb push_back
#define rsz resize
#define sz(x) int(x.size())
#define all(x) begin(x), end(x)
#define fi first
#define se second
// subtask 1
int const N=5e2+3;
int a[N],b[N];
int const D=1e6+3;
ll dp[N][D];
ll mod =1e9+7;
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int n;
cin>>n;
set<int> st;
F0R(i,n)
{
cin>>a[i]>>b[i];
FOR(j,a[i],b[i]+1)
{
st.insert(j);
}
}
vi v(all(st));
map<int,int>mp;
F0R(i,sz(st))
{
mp[v[i]]=i+1;
}
F0R(i,n)
{
a[i]=mp[a[i]];
b[i]=mp[b[i]];
}
F0R(j,sz(st)+1)
{
dp[0][j]=0;
}
dp[0][0]=1;
F0R(i,n)
{
F0R(j,n+1)
{
dp[i+1][j]=dp[i][j];
}
ll sum=0;
F0R(j,b[i]+1)
{
if(j>=a[i])
{
dp[i+1][j]+=sum;
dp[i+1][j]%=mod;
}
sum += dp[i][j];
sum%=mod;
}
}
ll ans=0;
FOR(j,1,sz(st)+1)
{
ans+=dp[n][j];
ans%=mod;
}
cout<<ans<<'\n';
return 0;
}
Compilation message
/tmp/ccgjbbNP.o: In function `main':
boat.cpp:(.text.startup+0x38): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cin' defined in .bss._ZSt3cin section in /usr/lib/gcc/x86_64-linux-gnu/9/libstdc++.a(globals_io.o)
boat.cpp:(.text.startup+0x3f): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cin' defined in .bss._ZSt3cin section in /usr/lib/gcc/x86_64-linux-gnu/9/libstdc++.a(globals_io.o)
boat.cpp:(.text.startup+0x87): relocation truncated to fit: R_X86_64_PC32 against symbol `a' defined in .bss section in /tmp/ccgjbbNP.o
boat.cpp:(.text.startup+0x8e): relocation truncated to fit: R_X86_64_PC32 against symbol `b' defined in .bss section in /tmp/ccgjbbNP.o
boat.cpp:(.text.startup+0x9e): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cin' defined in .bss._ZSt3cin section in /usr/lib/gcc/x86_64-linux-gnu/9/libstdc++.a(globals_io.o)
boat.cpp:(.text.startup+0x328): relocation truncated to fit: R_X86_64_PC32 against symbol `b' defined in .bss section in /tmp/ccgjbbNP.o
boat.cpp:(.text.startup+0x32f): relocation truncated to fit: R_X86_64_PC32 against symbol `a' defined in .bss section in /tmp/ccgjbbNP.o
boat.cpp:(.text.startup+0x4b8): relocation truncated to fit: R_X86_64_PC32 against symbol `b' defined in .bss section in /tmp/ccgjbbNP.o
boat.cpp:(.text.startup+0x4c8): relocation truncated to fit: R_X86_64_PC32 against symbol `a' defined in .bss section in /tmp/ccgjbbNP.o
boat.cpp:(.text.startup+0x5ea): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cout' defined in .bss._ZSt4cout section in /usr/lib/gcc/x86_64-linux-gnu/9/libstdc++.a(globals_io.o)
/tmp/ccgjbbNP.o: In function `_GLOBAL__sub_I_a':
boat.cpp:(.text.startup+0x6b7): additional relocation overflows omitted from the output
/usr/bin/ld: failed to convert GOTPCREL relocation; relink with --no-relax
collect2: error: ld returned 1 exit status
