#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(random_device{}());
const ll mod=1000000007;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head
const int N=30100;
int n,m,b[N],p[N];
ll d[N];
VI qs[N];
int main() {
scanf("%d%d",&n,&m);
rep(i,0,m) {
scanf("%d%d",b+i,p+i);
qs[b[i]].pb(p[i]);
}
rep(i,0,n) d[i]=(1LL<<59);
priority_queue<pair<ll,int>> q;
q.push(mp(0,b[0])); d[b[0]]=0;
while (SZ(q)) {
auto x=q.top(); q.pop();
if (d[x.se]<-x.fi) continue;
for (int j:qs[x.se]) {
for (int u=x.se-j;u>=0,ft=1;u-=j,ft++) {
if (d[u]>d[x.se]+ft) {
d[u]=d[x.se]+ft;
q.push(mp(-d[u],u));
}
}
for (int u=x.se+j;u<n,ft=1;u+=j,ft++) {
if (d[u]>d[x.se]+ft) {
d[u]=d[x.se]+ft;
q.push(mp(-d[u],u));
}
}
}
}
if (d[b[1]]==(1LL<<59)) printf("-1");
else printf("%lld",d[b[1]]);
}
Compilation message
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:39:27: error: 'ft' was not declared in this scope; did you mean 'fi'?
39 | for (int u=x.se-j;u>=0,ft=1;u-=j,ft++) {
| ^~
| fi
skyscraper.cpp:45:26: error: 'ft' was not declared in this scope; did you mean 'fi'?
45 | for (int u=x.se+j;u<n,ft=1;u+=j,ft++) {
| ^~
| fi
skyscraper.cpp:27:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | scanf("%d%d",&n,&m);
| ~~~~~^~~~~~~~~~~~~~
skyscraper.cpp:29:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
29 | scanf("%d%d",b+i,p+i);
| ~~~~~^~~~~~~~~~~~~~~~
