Language: C++

#pragma GCC optimize ("O3")

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <set>
#include <algorithm>
#include <numeric>
#include <list>
using namespace std;

using QWORD  = uint64_t;
using SQWORD = int64_t;
using DWORD  = uint32_t;
using SDWORD = int32_t;
using WORD   = uint16_t;
using SWORD  = int16_t;
using BYTE   = uint8_t;
using SBYTE  = int8_t;
using DOUBLE = double;
using FLOAT  = float;

#define MIN_SDWORD (-2147483648)
#define MAX_SDWORD (2147483647)
#define MIN_SBYTE (-128)
#define MAX_SBYTE (127)

#define MIN_SQWORD (0x8000000000000000)
#define MAX_SQWORD (0x7FFFFFFFFFFFFFFF)

#define MAX_QWORD  (0xFFFFFFFFFFFFFFFF)
#define MAX_DWORD  (0xFFFFFFFF)
#define MAX_WORD   (0xFFFF)
#define MAX_BYTE   (0xFF)


#define ArrayLength(a)  (sizeof(a) / sizeof(a[0]))

static inline QWORD MAX(QWORD a, QWORD b) { return a > b ? a : b; }
static inline DWORD MAX(DWORD a, DWORD b) { return a > b ? a : b; }
static inline SDWORD MAX(SDWORD a, SDWORD b) { return a > b ? a : b; }
static inline QWORD MIN(QWORD a, QWORD b) { return a < b ? a : b; }
static inline DWORD MIN(DWORD a, DWORD b) { return a < b ? a : b; }
static inline SDWORD MIN(SDWORD a, SDWORD b) { return a < b ? a : b; }

#define BYTE_BITS   (8)
#define WORD_BITS   (16)
#define DWORD_BITS  (32)
#define QWORD_BITS  (64)

using M_BOOL = bool;
#define M_TRUE (true)
#define M_FALSE (false)
#define DIVISOR (1000000007)

static inline void inputString(char *pcStr)
{
    char *pcCur = pcStr;
    for (;;) {
        char c = getchar();
        if (('\n' == c) || (EOF == c)) {
            break;
        }
        *pcCur = c;
        pcCur++;
    }
    *pcCur = '\0';
}


static inline SQWORD inputSQWORD(void)
{
    SQWORD sqNumber = 0;
    SQWORD sqMultiplier = 1;
    M_BOOL bRead = M_FALSE;
    for (;;) {
        char c = getchar();
        if (!bRead) {
            if ('-' == c) {
                sqMultiplier = -1;
            }
        }
        if (('0' <= c) && (c <= '9')) {
            sqNumber *= 10LL;
            sqNumber += (SQWORD)(c - '0');
            bRead = M_TRUE;
        } else {
            if (bRead) {
                return sqNumber * sqMultiplier;
            }
        }
    }
}


static inline SDWORD inputSDWORD(void)
{
    SDWORD lNumber = 0;
    SDWORD lMultiplier = 1;
    M_BOOL bRead = M_FALSE;
    for (;;) {
        char c = getchar();
        if (!bRead) {
            if ('-' == c) {
                lMultiplier = -1;
            }
        }
        if (('0' <= c) && (c <= '9')) {
            lNumber *= 10;
            lNumber += (c - '0');
            bRead = M_TRUE;
        } else {
            if (bRead) {
                return lNumber * lMultiplier;
            }
        }
    }
}

static inline DOUBLE inputFP(void)
{
    DOUBLE dInt = 0.0;
    DOUBLE dFrac = 0.0;
    DOUBLE dMultiplier = 1.0;
    DWORD dwFpCnt = 0;
    DOUBLE *pdCur = &dInt;
    M_BOOL bRead = M_FALSE;
    for (;;) {
        char c = getchar();
        if (!bRead) {
            if ('-' == c) {
                dMultiplier = -1;
            }
        }
        if ('.' == c) {
            pdCur = &dFrac;
        } else if (('0' <= c) && (c <= '9')) {
            (*pdCur) *= 10;
            (*pdCur) += (DOUBLE)(c - '0');
            bRead = M_TRUE;
            if (pdCur == &dFrac) {
                dwFpCnt++;
            }
        } else {
            if (bRead) {
                return dMultiplier * (dInt + dFrac / (pow((DOUBLE)10.0 , (DOUBLE)dwFpCnt)));
            }
        }
    }
}


/**
 *  mod による操作ライブラリ
 */

#define ANS_MOD (1000000007LL)
 
static SQWORD addMod(SQWORD x, SQWORD y)
{ 
    return (x + y) % ANS_MOD;
}
 
static SQWORD subMod(SQWORD x, SQWORD y)
{
    return (x - y + ANS_MOD) % ANS_MOD;
}
 
static SQWORD mulMod(SQWORD x, SQWORD y) 
{
    return (x * y) % ANS_MOD;
}
 
static SQWORD powMod(SQWORD x, SQWORD e) {
    SQWORD v = 1;
    for (; e; x = mulMod(x, x), e >>= 1) {
        if (e & 1) {
            v = mulMod(v, x);
        }
    }
    return v;
}
 
static SQWORD divMod(SQWORD x, SQWORD y)
{
    return mulMod(x, powMod(y, ANS_MOD - 2));
}
 
 
static SQWORD combMod(SQWORD n, SQWORD k)
{
    SQWORD v=1;
    for(SQWORD i=1; i<=k; i++) {
        v = divMod(mulMod(v, n-i+1),i);
    } 
    return v;
}

/*----------------------------------------------*/

#define MAX_V           (100000)
#define SQWORD_INF      (1000000000000000000)

struct EDGE_ST {
    SQWORD sqTo;
    SQWORD sqCost;

    EDGE_ST(SQWORD to, SQWORD cost) {
        sqTo = to;
        sqCost = cost;
    };
};

void getNextPnts(SDWORD lStart, const vector<EDGE_ST> *pvstEdges, set<SQWORD> &setNextPnts)
{
    for (auto edge1: pvstEdges[lStart]) {
        for (auto edge2: pvstEdges[edge1.sqTo]) {
            for (auto edge3: pvstEdges[edge2.sqTo]) {
//                printf("-->%lld\n", edge3.sqTo);
                setNextPnts.insert(edge3.sqTo);
            }
        }
    }
}

void execQuery(SQWORD sqFrom, SQWORD sqTo, const vector<EDGE_ST> *pvstEdges)
{
    typedef pair<SDWORD, SDWORD> P;
    vector<SQWORD> cost(MAX_V + 1, SQWORD_INF);
    priority_queue<P, vector<P>, greater<P>> que;
    
    cost[sqFrom] = 0;
    que.push(P(0, sqFrom));

    while (!que.empty()) {
        P p = que.top();
        que.pop();

        SDWORD v = p.second;
        if (p.first <= cost[v]) {
            for (SDWORD lIdx = 0; lIdx < pvstEdges[v].size(); lIdx++) {
                EDGE_ST e = pvstEdges[v][lIdx];

                if (cost[e.sqTo] > cost[v] + e.sqCost) {
                    cost[e.sqTo] = cost[v] + e.sqCost;
                    que.push(P(cost[e.sqTo], e.sqTo));
                }
            }
        }
    }

    SQWORD sqLastHeight;
    if (cost[sqTo] == SQWORD_INF) {
        printf("-1\n");
    } else {
        printf("%lld\n", (SQWORD)cost[sqTo]);
    }
}


int main()
{
    SQWORD sqInput_N = inputSQWORD();       /* number of islands */
    SQWORD sqInput_M = inputSQWORD();       /* number of queries */
    vector<EDGE_ST> vstEdgesRaw[sqInput_N + 1];
    vector<EDGE_ST> vstEdges3[sqInput_N + 1];


//    printf("n:%lld m:%lld x:%lld\n", sqInput_N, sqInput_N, sqInput_X);

    for (SQWORD sqIdx = 0; sqIdx < sqInput_M; sqIdx++) {
        SQWORD sq_u = inputSQWORD();
        SQWORD sq_v = inputSQWORD();
        vstEdgesRaw[sq_u].emplace_back(EDGE_ST(sq_v, 1));
    }

    for (SQWORD sqPnt = 0; sqPnt <= sqInput_N; sqPnt++) {
        set<SQWORD> setsqNextPnts;

        getNextPnts(sqPnt, vstEdgesRaw, setsqNextPnts);
        for (auto pnt: setsqNextPnts) {
            vstEdges3[sqPnt].emplace_back(pnt);
        }
    }

    SQWORD sqInput_S = inputSQWORD();
    SQWORD sqInput_T = inputSQWORD();
    execQuery(sqInput_S, sqInput_T, vstEdges3);
    
    return 0;
}



Compiler output:
a.cc:19:16: error: 'uint64_t' does not name a type
   19 | using QWORD  = uint64_t;
      |                ^~~~~~~~
a.cc:17:1: note: 'uint64_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
   16 | #include <list>
  +++ |+#include <cstdint>
   17 | using namespace std;
a.cc:21:16: error: 'uint32_t' does not name a type
   21 | using DWORD  = uint32_t;
      |                ^~~~~~~~
a.cc:21:16: note: 'uint32_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
a.cc:23:16: error: 'uint16_t' does not name a type
   23 | using WORD   = uint16_t;
      |                ^~~~~~~~
a.cc:23:16: note: 'uint16_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
a.cc:25:16: error: 'uint8_t' does not name a type
   25 | using BYTE   = uint8_t;
      |                ^~~~~~~
a.cc:25:16: note: 'uint8_t' is defined in header '<cstdint>'; this is probably fixable by adding '#include <cstdint>'
a.cc:46:15: error: 'QWORD' does not name a type; did you mean 'SWORD'?
   46 | static inline QWORD MAX(QWORD a, QWORD b) { return a > b ? a : b; }
      |               ^~~~~
      |               SWORD
a.cc:47:15: error: 'DWORD' does not name a type; did you mean 'SWORD'?
   47 | static inline DWORD MAX(DWORD a, DWORD b) { return a > b ? a : b; }
      |               ^~~~~
      |               SWORD
a.cc:49:15: error: 'QWORD' does not name a type; did you mean 'SWORD'?
   49 | static inline QWORD MIN(QWORD a, QWORD b) { return a < b ? a : b; }
      |               ^~~~~
      |               SWORD
a.cc:50:15: error: 'DWORD' does not name a type; did you mean 'SWORD'?
   50 | static inline DWORD MIN(DWORD a, DWORD b) { return a < b ? a : b; }
      |               ^~~~~
      |               SWORD
a.cc: In function 'DOUBLE inputFP()':
a.cc:132:5: error: 'DWORD' was not declared in this scope; did you mean 'SWORD'?
  132 |     DWORD dwFpCnt = 0;
      |     ^~~~~
      |     SWORD
a.cc:149:17: error: 'dwFpCnt' was not declared in this scope
  149 |                 dwFpCnt++;
      |                 ^~~~~~~
a.cc:153:82: error: 'dwFpCnt' was not declared in this scope
  153 |                 return dMultiplier * (dInt + dFrac / (pow((DOUBLE)10.0 , (DOUBLE)dwFpCnt)));
      |                                                                                  ^~~~~~~
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/c++allocator.h:33,
                 from /usr/include/c++/14/bits/allocator.h:46,
                 from /usr/include/c++/14/string:43,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:3:
/usr/include/c++/14/bits/new_allocator.h: In instantiation of 'void std::__new_allocator<_Tp>::construct(_Up*, _Args&& ...) [with _Up = EDGE_ST; _Args = {long int&}; _Tp = EDGE_ST]':
/usr/include/c++/14/bits/alloc_traits.h:575:17:   required from 'static void std::allocator_traits<std::allocator<_CharT> >::construct(allocator_type&, _Up*, _Args&& ...) [with _Up = EDGE_ST; _Args = {long int&}; _Tp = EDGE_ST; allocator_type = std::allocator<EDGE_ST>]'
  575 |           __a.construct(__p, std::forward<_Args>(__args)...);
      |           ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/bits/vector.tcc:117:30:   required from 'std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::emplace_back(_Args&& ...) [with _Args = {long int&}; _Tp = EDGE_ST; _Alloc = std::allocator<EDGE_ST>; reference = EDGE_ST&]'
  117 |             _Alloc_traits::construct(this->_M_impl, this->_M_impl._M_finish,
      |             ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  118 |                                      std::forward<_Args>(__args)...);
      |                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:289:42:   required from here
  289 |             vstEdges3[sqPnt].emplace_back(pnt);
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
/usr/include/c++/14/bits/new_allocator.h:191:11: error: no matching function for call to 'EDGE_ST::EDGE_ST(long int&)'
  191 |         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:215:5: note: candidate: 'EDGE_ST::EDGE_ST(SQWORD, SQWORD)'
  215 |     EDGE_ST(SQWORD to, SQWORD cost) {
      |     ^~~~~~~
a.cc:215:5: note:   candidate expects 2 arguments, 1 provided
a.cc:211:8: note: candidate: 'constexpr EDGE_ST::EDGE_ST(const EDGE_ST&)'
  211 | struct EDGE_ST {
      |        ^~~~~~~
a.cc:211:8: note:   no known conversion for argument 1 from 'long int' to 'const EDGE_ST&'
a.cc:211:8: note: candidate: 'constexpr EDGE_ST::EDGE_ST(EDGE_ST&&)'
a.cc:211:8: note:   no known conversion for argument 1 from 'long int' to 'EDGE_ST&&'