Submission #306389

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Source Code Expand

#include<stdio.h>
#include<vector>
#include<string.h>
#include<queue>
#include<algorithm>
using namespace std;
namespace MCF {
	// required <string.h> <vector> <queue> <algorithm>
	#define MAXN 110000
	#define MAXM 110000
	#define wint int
	#define cint int
	const wint wEPS = 0;
	const wint wINF = 1001001001;
	const cint cEPS = 0;
	const cint cINF = 1001001001;
	int col[MAXM];
	int n, m, ptr[MAXN], next[MAXM], zu[MAXM];
	wint capa[MAXM], tof;
	cint cost[MAXM], toc, d[MAXN], pot[MAXN];
	int vis[MAXN], pree[MAXN];
	void init(int _n) {
		n = _n; m = 0; memset(ptr, ~0, n * 4);
	}
	void ae(int u, int v, wint w, cint c) {
		next[m] = ptr[u]; ptr[u] = m; zu[m] = v; capa[m] = w; cost[m] = +c;col[m]=0; ++m;
		next[m] = ptr[v]; ptr[v] = m; zu[m] = u; capa[m] = 0; cost[m] = -c;col[m]=1; ++m;
	}
	bool solve(int src, int ink, wint flo = wINF) {
		int i, u, v;
		wint f;
		cint c, cc;
		memset(pot, 0, n * sizeof(cint));
		//*
		for (bool cont = 1; cont; ) {
			cont = 0;
			for (u = 0; u < n; ++u) for (i = ptr[u]; ~i; i = next[i]) if (capa[i] > wEPS) {
				if (pot[zu[i]] > pot[u] + cost[i] + cEPS) {
					pot[zu[i]] = pot[u] + cost[i]; cont = 1;
				}
			}
		}
		//*/
		for (toc = 0, tof = 0; tof + wEPS < flo; ) {
			typedef pair<cint,int> node;
			priority_queue< node,vector<node>,greater<node> > q;
			for (u = 0; u < n; ++u) { d[u] = cINF; vis[u] = 0; }
			for (q.push(make_pair(d[src] = 0, src)); !q.empty(); ) {
				c = q.top().first; u = q.top().second; q.pop();
				if (vis[u]++) continue;
				for (i = ptr[u]; ~i; i = next[i]) if (capa[i] > wEPS) {
					cc = c + cost[i] + pot[u] - pot[v = zu[i]];
					if (d[v] > cc + cEPS) { q.push(make_pair(d[v] = cc, v)); pree[v] = i; }
				}
			}
			if (!vis[ink]) return 0;
			f = flo - tof;
			for (v = ink; v != src; v = zu[i ^ 1]) { i = pree[v]; f=min(f,capa[i]); }
			for (v = ink; v != src; v = zu[i ^ 1]) { i = pree[v]; capa[i] -= f; capa[i ^ 1] += f; }
			tof += f;
			toc += f * (d[ink] - pot[src] + pot[ink]);
			for (u = 0; u < n; ++u) pot[u] += d[u];
		}
		return 1;
	}
}
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
char str[100][100];
int bfs[100][100];
int main(){
	int a,b;
	scanf("%d%d",&a,&b);
	for(int i=0;i<a;i++)scanf("%s",str[i]);
	for(int i=0;i<100;i++)for(int j=0;j<100;j++)bfs[i][j]=-1;
	queue<pair<int,int> > Q;
	int sr,sc;
	int ar,ac;
	int br,bc;
	for(int i=0;i<a;i++)for(int j=0;j<b;j++){
		if(str[i][j]=='S'){sr=i;sc=j;}
		if(str[i][j]=='A'){ar=i;ac=j;}
		if(str[i][j]=='B'){br=i;bc=j;}
	}
	Q.push(make_pair(sr,sc));
	bfs[sr][sc]=0;
	while(Q.size()){
		int row=Q.front().first;
		int col=Q.front().second;
		Q.pop();
		for(int i=0;i<4;i++){
			if(0<=row+dx[i]&&row+dx[i]<a&&0<=col+dy[i]&&col+dy[i]<b&&!~bfs[row+dx[i]][col+dy[i]]&&str[row+dx[i]][col+dy[i]]!='#'){
				bfs[row+dx[i]][col+dy[i]]=bfs[row][col]+1;
				Q.push(make_pair(row+dx[i],col+dy[i]));
			}
		}
	}
	int ad=bfs[ar][ac];
	int bd=bfs[br][bc];
	MCF::init(a*b*2+1);
	for(int i=0;i<a;i++)for(int j=0;j<b;j++){
		MCF::ae(2*(i*b+j),2*(i*b+j)+1,1,0);
		for(int k=0;k<4;k++){
			if(0<=i+dx[k]&&i+dx[k]<a&&0<=j+dy[k]&&j+dy[k]<b&&str[i+dx[k]][j+dy[k]]!='#'){
				MCF::ae(2*(i*b+j)+1,2*((i+dx[k])*b+j+dy[k]),1,1);
			}
		}
	}
	MCF::ae(2*(ar*b+ac)+1,a*b*2,1,0);
	MCF::ae(2*(br*b+bc)+1,a*b*2,1,0);
	int res=MCF::solve(2*(sr*b+sc)+1,a*b*2,2);
	if(!res||MCF::toc>ad+bd){
		printf("NA\n");return 0;
	}
	int nr=ar;
	int nc=ac;
	while(1){
		int t=2*(nr*b+nc);
		int to;
		for(int i=MCF::ptr[t];~i;i=MCF::next[i]){
			if(MCF::col[i]&&MCF::capa[i]){
				to=MCF::zu[i]/2;
				break;
			}
		}
		int tr=to/b;
		int tc=to%b;
		if(sr==tr&&sc==tc)break;
		str[tr][tc]='a';
		nr=tr;nc=tc;
	}
	 nr=br;
	 nc=bc;
	while(1){
		int t=2*(nr*b+nc);
		int to;
		for(int i=MCF::ptr[t];~i;i=MCF::next[i]){
			if(MCF::col[i]&&MCF::capa[i]){
				to=MCF::zu[i]/2;
				break;
			}
		}
		int tr=to/b;
		int tc=to%b;
		if(sr==tr&&sc==tc)break;
		str[tr][tc]='b';
		nr=tr;nc=tc;
	}
	for(int i=0;i<a;i++)printf("%s\n",str[i]);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:73:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
./Main.cpp:74:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]

Judge Result