Problem p01543 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <string>
#include <vector>
//    #include <boost/multiprecision/cpp_int.hpp>
#include <functional>
#define int long long
#define inf 1000000007
#define pa pair<int, int>
#define ll long long
#define pal pair<double, pa>
#define ppap pair<pa, int>

#define ssa pair<string, int>
#define mp make_pair
#define pb push_back
#define EPS (1e-10)
#define equals(a, b) (fabs((a) - (b)) < EPS)
int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};
using namespace std;
class pas {
public:
  int x, y, h;
  pas(int x = 0, int y = 0, int h = 0) : x(x), y(y), h(h) {}
  bool operator<(const pas &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pas &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};
class pa2 {
public:
  int x, y;
  pa2(int x = 0, int y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  bool operator<(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};

#define ppa pair<int, pas>
class Point {
public:
  double x, y;
  Point(double x = 0, double y = 0) : x(x), y(y) {}
  Point operator+(Point p) { return Point(x + p.x, y + p.y); }
  Point operator-(Point p) { return Point(x - p.x, y - p.y); }
  Point operator*(double a) { return Point(x * a, y * a); }
  Point operator/(double a) { return Point(x / a, y / a); }
  double absv() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  bool operator<(const Point &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const Point &p) const {
    return fabs(x - p.x) < EPS && fabs(y - p.y) < EPS;
  }
};
typedef Point Vector;
#define pl pair<int, pas>
struct Segment {
  Point p1, p2;
};
double dot(Vector a, Vector b) { return a.x * b.x + a.y * b.y; }
double cross(Vector a, Vector b) { return a.x * b.y - a.y * b.x; }

bool parareru(Point a, Point b, Point c, Point d) {
  //	if(abs(cross(a-b,d-c))<EPS)cout<<"dd "<<cross(a-b,d-c)<<endl;
  return abs(cross(a - b, d - c)) < EPS;
}
double distance_ls_p(Point a, Point b, Point c) {
  if (dot(b - a, c - a) < EPS)
    return (c - a).absv();
  if (dot(a - b, c - b) < EPS)
    return (c - b).absv();
  return abs(cross(b - a, c - a)) / (b - a).absv();
}
bool is_intersected_ls(Segment a, Segment b) {
  if (a.p1 == b.p1 || a.p2 == b.p1 || a.p1 == b.p2 || a.p2 == b.p2)
    return false;
  if (parareru((a.p2), (a.p1), (a.p1), (b.p2)) &&
      parareru((a.p2), (a.p1), (a.p1), (b.p1))) {
    //		cout<<"sss"<<endl;
    if (dot(a.p1 - b.p1, a.p1 - b.p2) < EPS)
      return true;
    if (dot(a.p2 - b.p1, a.p2 - b.p2) < EPS)
      return true;
    if (dot(a.p1 - b.p1, a.p2 - b.p1) < EPS)
      return true;
    if (dot(a.p1 - b.p2, a.p2 - b.p2) < EPS)
      return true;
    return false;
  } else
    return (cross(a.p2 - a.p1, b.p1 - a.p1) * cross(a.p2 - a.p1, b.p2 - a.p1) <
            EPS) &&
           (cross(b.p2 - b.p1, a.p1 - b.p1) * cross(b.p2 - b.p1, a.p2 - b.p1) <
            EPS);
}

double segment_dis(Segment a, Segment b) {
  if (is_intersected_ls(a, b))
    return 0;
  double r = distance_ls_p(a.p1, a.p2, b.p1);
  r = min(r, distance_ls_p(a.p1, a.p2, b.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p1));
  return r;
}
Point intersection_ls(Segment a, Segment b) {
  Point ba = b.p2 - b.p1;
  double d1 = abs(cross(ba, a.p1 - b.p1));
  double d2 = abs(cross(ba, a.p2 - b.p1));
  double t = d1 / (d1 + d2);

  return a.p1 + (a.p2 - a.p1) * t;
}

string itos(int i) {
  ostringstream s;
  s << i;
  return s.str();
}

int gcd(int v, int b) {
  if (v > b)
    return gcd(b, v);
  if (v == b)
    return b;
  if (b % v == 0)
    return v;
  return gcd(v, b % v);
}

double distans(double x1, double y1, double x2, double y2) {
  double rr = (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
  return sqrt(rr);
}

//         int pr[2000010];
//       int inv[2000010];
/*
int beki(int wa,int rr,int warukazu){
    if(rr==0) return 1ll;
    if(rr==1) return wa%warukazu;
    if(rr%2==1) return (beki(wa,rr-1,warukazu)*wa)%warukazu;
    int zx=beki(wa,rr/2,warukazu);
    return (zx*zx)%warukazu;
}

            int comb(int nn,int rr){
                    int r=pr[nn]*inv[rr];
                    r%=inf;
                    r*=inv[nn-rr];
                    r%=inf;
                    return r;
            }

void gya(int ert){
    pr[0]=1;
    for(int i=1;i<ert;i++){
            pr[i]=(pr[i-1]*i)%inf;
    }
    for(int i=0;i<ert;i++) inv[i]=beki(pr[i],inf-2,inf);

}
 */

// sort(ve.begin(),ve.end(),greater<int>());
//----------------kokomade tenpure------------
// vector<double> ans(100000000),ans2(100000000);

typedef pair<int, int> P;
struct edge {
  int to, cap, cost, rev;
};
vector<edge> G[50010];
bool used[50010];
int h[50010], dist[50010], prevv[50010], preve[50010];
int V; // Vは頂点数

void add_edge(int from, int to, int cap, int cost) {
  G[from].push_back((edge){to, cap, cost, (ll)G[to].size()});
  G[to].push_back((edge){from, 0, -cost, (ll)G[from].size() - 1});
}

int min_cost_flow(int s, int t, int f) {
  int res = 0;
  fill(h, h + V, 0);
  while (f > 0) {

    priority_queue<P, vector<P>, greater<P>> que;
    fill(dist, dist + V, inf);
    dist[s] = 0;
    que.push(P(0, s));
    while (!que.empty()) {
      P p = que.top();
      que.pop();
      int v = p.second;
      if (dist[v] < p.first)
        continue;
      for (int i = 0; i < G[v].size(); i++) {
        edge &e = G[v][i];
        if (e.cap > 0 && dist[e.to] > dist[v] + e.cost + h[v] - h[e.to]) {
          dist[e.to] = dist[v] + e.cost + h[v] - h[e.to];
          prevv[e.to] = v;
          preve[e.to] = i;
          que.push(P(dist[e.to], e.to));
        }
      }
    }
    if (dist[t] == inf)
      return -1;
    for (int v = 0; v < V; v++)
      h[v] += dist[v];
    int d = f;
    for (int v = t; v != s; v = prevv[v]) {
      d = min(d, G[prevv[v]][preve[v]].cap);
    }
    f -= d;
    res += d * h[t];
    for (int v = t; v != s; v = prevv[v]) {
      edge &e = G[prevv[v]][preve[v]];
      e.cap -= d;
      G[v][e.rev].cap += d;
    }
  }
  return res;
}
vector<pa> ans;
int w[101][110], e[110][110], a[110][110];
signed main() {
  int n;
  cin >> n;
  V = 300;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++)
      cin >> w[i][j];
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++)
      cin >> e[i][j];

  for (int i = 1; i <= n; i++) {
    string s;
    cin >> s;

    s = "q" + s;
    for (int j = 1; j <= n; j++) {
      if (s[j] == 'o')
        a[i][j] = 1;
      else
        a[i][j] = 0;
    }
  }

  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++) {
      int gosa = 0;
      for (int k = 1; k <= n; k++)
        if (k != j) {
          if (a[i][k] == 1)
            gosa += e[i][k];
        }
      if (a[i][j] == 0)
        gosa += w[i][j];

      add_edge(i, n + j, 1, gosa);
    }

  for (int i = 1; i <= n; i++) {
    add_edge(0, i, 1, 0);
    add_edge(n + i, 2 * n + 1, 1, 0);
  }

  cout << min_cost_flow(0, 2 * n + 1, n) << endl;
  for (int i = 1; i < n + 1; i++)
    for (auto e : G[i]) {
      if (e.to == 0)
        continue;
      if (e.cap == 1 && a[i][e.to - n] == 1)
        ans.pb(mp(i, e.to));
      if (e.cap == 0 && a[i][e.to - n] == 0)
        ans.pb(mp(i, e.to));
    }
  cout << ans.size() << endl;
  for (auto v : ans) {
    if (a[v.first][v.second - n])
      cout << v.first << " " << v.second - n << " erase" << endl;
    else
      cout << v.first << " " << v.second - n << " write" << endl;
  }
  return 0;
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <string>
#include <vector>
//    #include <boost/multiprecision/cpp_int.hpp>
#include <functional>
#define int long long
#define inf 1000000007
#define pa pair<int, int>
#define ll long long
#define pal pair<double, pa>
#define ppap pair<pa, int>

#define ssa pair<string, int>
#define mp make_pair
#define pb push_back
#define EPS (1e-10)
#define equals(a, b) (fabs((a) - (b)) < EPS)
int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};
using namespace std;
class pas {
public:
  int x, y, h;
  pas(int x = 0, int y = 0, int h = 0) : x(x), y(y), h(h) {}
  bool operator<(const pas &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pas &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};
class pa2 {
public:
  int x, y;
  pa2(int x = 0, int y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  bool operator<(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
};

#define ppa pair<int, pas>
class Point {
public:
  double x, y;
  Point(double x = 0, double y = 0) : x(x), y(y) {}
  Point operator+(Point p) { return Point(x + p.x, y + p.y); }
  Point operator-(Point p) { return Point(x - p.x, y - p.y); }
  Point operator*(double a) { return Point(x * a, y * a); }
  Point operator/(double a) { return Point(x / a, y / a); }
  double absv() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  bool operator<(const Point &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const Point &p) const {
    return fabs(x - p.x) < EPS && fabs(y - p.y) < EPS;
  }
};
typedef Point Vector;
#define pl pair<int, pas>
struct Segment {
  Point p1, p2;
};
double dot(Vector a, Vector b) { return a.x * b.x + a.y * b.y; }
double cross(Vector a, Vector b) { return a.x * b.y - a.y * b.x; }

bool parareru(Point a, Point b, Point c, Point d) {
  //	if(abs(cross(a-b,d-c))<EPS)cout<<"dd "<<cross(a-b,d-c)<<endl;
  return abs(cross(a - b, d - c)) < EPS;
}
double distance_ls_p(Point a, Point b, Point c) {
  if (dot(b - a, c - a) < EPS)
    return (c - a).absv();
  if (dot(a - b, c - b) < EPS)
    return (c - b).absv();
  return abs(cross(b - a, c - a)) / (b - a).absv();
}
bool is_intersected_ls(Segment a, Segment b) {
  if (a.p1 == b.p1 || a.p2 == b.p1 || a.p1 == b.p2 || a.p2 == b.p2)
    return false;
  if (parareru((a.p2), (a.p1), (a.p1), (b.p2)) &&
      parareru((a.p2), (a.p1), (a.p1), (b.p1))) {
    //		cout<<"sss"<<endl;
    if (dot(a.p1 - b.p1, a.p1 - b.p2) < EPS)
      return true;
    if (dot(a.p2 - b.p1, a.p2 - b.p2) < EPS)
      return true;
    if (dot(a.p1 - b.p1, a.p2 - b.p1) < EPS)
      return true;
    if (dot(a.p1 - b.p2, a.p2 - b.p2) < EPS)
      return true;
    return false;
  } else
    return (cross(a.p2 - a.p1, b.p1 - a.p1) * cross(a.p2 - a.p1, b.p2 - a.p1) <
            EPS) &&
           (cross(b.p2 - b.p1, a.p1 - b.p1) * cross(b.p2 - b.p1, a.p2 - b.p1) <
            EPS);
}

double segment_dis(Segment a, Segment b) {
  if (is_intersected_ls(a, b))
    return 0;
  double r = distance_ls_p(a.p1, a.p2, b.p1);
  r = min(r, distance_ls_p(a.p1, a.p2, b.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p1));
  return r;
}
Point intersection_ls(Segment a, Segment b) {
  Point ba = b.p2 - b.p1;
  double d1 = abs(cross(ba, a.p1 - b.p1));
  double d2 = abs(cross(ba, a.p2 - b.p1));
  double t = d1 / (d1 + d2);

  return a.p1 + (a.p2 - a.p1) * t;
}

string itos(int i) {
  ostringstream s;
  s << i;
  return s.str();
}

int gcd(int v, int b) {
  if (v > b)
    return gcd(b, v);
  if (v == b)
    return b;
  if (b % v == 0)
    return v;
  return gcd(v, b % v);
}

double distans(double x1, double y1, double x2, double y2) {
  double rr = (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
  return sqrt(rr);
}

//         int pr[2000010];
//       int inv[2000010];
/*
int beki(int wa,int rr,int warukazu){
    if(rr==0) return 1ll;
    if(rr==1) return wa%warukazu;
    if(rr%2==1) return (beki(wa,rr-1,warukazu)*wa)%warukazu;
    int zx=beki(wa,rr/2,warukazu);
    return (zx*zx)%warukazu;
}

            int comb(int nn,int rr){
                    int r=pr[nn]*inv[rr];
                    r%=inf;
                    r*=inv[nn-rr];
                    r%=inf;
                    return r;
            }

void gya(int ert){
    pr[0]=1;
    for(int i=1;i<ert;i++){
            pr[i]=(pr[i-1]*i)%inf;
    }
    for(int i=0;i<ert;i++) inv[i]=beki(pr[i],inf-2,inf);

}
 */

// sort(ve.begin(),ve.end(),greater<int>());
//----------------kokomade tenpure------------
// vector<double> ans(100000000),ans2(100000000);

typedef pair<int, int> P;
struct edge {
  int to, cap, cost, rev;
};
vector<edge> G[50010];
bool used[50010];
int h[50010], dist[50010], prevv[50010], preve[50010];
int V; // Vは頂点数

void add_edge(int from, int to, int cap, int cost) {
  G[from].push_back((edge){to, cap, cost, (ll)G[to].size()});
  G[to].push_back((edge){from, 0, -cost, (ll)G[from].size() - 1});
}

int min_cost_flow(int s, int t, int f) {
  int res = 0;
  fill(h, h + V, 0);
  while (f > 0) {
    priority_queue<P, vector<P>, greater<P>> que;
    fill(dist, dist + V, inf);
    dist[s] = 0;
    que.push(P(0, s));
    while (!que.empty()) {
      P p = que.top();
      que.pop();
      int v = p.second;
      if (dist[v] < p.first)
        continue;
      for (int i = 0; i < G[v].size(); i++) {
        edge &e = G[v][i];
        if (e.cap > 0 && dist[e.to] > dist[v] + e.cost + h[v] - h[e.to]) {
          dist[e.to] = dist[v] + e.cost + h[v] - h[e.to];
          prevv[e.to] = v;
          preve[e.to] = i;
          que.push(P(dist[e.to], e.to));
        }
      }
    }
    if (dist[t] == inf)
      return -1;
    for (int v = 0; v < V; v++)
      h[v] += dist[v];
    int d = f;
    for (int v = t; v != s; v = prevv[v]) {
      d = min(d, G[prevv[v]][preve[v]].cap);
    }
    f -= d;
    res += d * h[t];
    for (int v = t; v != s; v = prevv[v]) {
      edge &e = G[prevv[v]][preve[v]];
      e.cap -= d;
      G[v][e.rev].cap += d;
    }
  }
  return res;
}
vector<pa> ans;
int w[100][110], e[110][110], a[110][110];
signed main() {
  int n;
  cin >> n;
  V = 300;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++)
      cin >> w[i][j];
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++)
      cin >> e[i][j];

  for (int i = 1; i <= n; i++) {
    string s;
    cin >> s;

    s = "q" + s;
    for (int j = 1; j <= n; j++) {
      if (s[j] == 'o')
        a[i][j] = 1;
      else
        a[i][j] = 0;
    }
  }

  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++) {
      int gosa = 0;
      for (int k = 1; k <= n; k++)
        if (k != j) {
          if (a[i][k] == 1)
            gosa += e[i][k];
        }
      if (a[i][j] == 0)
        gosa += w[i][j];

      add_edge(i, n + j, 1, gosa);
    }

  for (int i = 1; i <= n; i++) {
    add_edge(0, i, 1, 0);
    add_edge(n + i, 2 * n + 1, 1, 0);
  }

  cout << min_cost_flow(0, 2 * n + 1, n) << endl;
  for (int i = 1; i < n + 1; i++)
    for (auto e : G[i]) {
      if (e.to == 0)
        continue;
      if (e.cap == 1 && a[i][e.to - n] == 1)
        ans.pb(mp(i, e.to));
      if (e.cap == 0 && a[i][e.to - n] == 0)
        ans.pb(mp(i, e.to));
    }
  cout << ans.size() << endl;
  for (auto v : ans) {
    if (a[v.first][v.second - n])
      cout << v.first << " " << v.second - n << " erase" << endl;
    else
      cout << v.first << " " << v.second - n << " write" << endl;
  }
  return 0;
}