Submission #2712122

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Source Code Expand

#include <bits/stdc++.h>
#define F(i,a,b) for(int i=(a);i<=(b);++i)
#define F_(i,a,b) for(int i=(a);i>=(b);--i)
#define G(i,u) for(int i=Head[a];i;i=Next[i])

typedef long long ll;
typedef double db;
typedef long double ld;

template<typename T> inline T max(T& a, T b) { return a>b?a:a=b; }
template<typename T> inline T min(T& a, T b) { return a<b?a:a=b; }

const int N = 5005; 

std::vector<int> ch[26*10];
char s[N], ans[N];
int cnt = -1, k, n, tot = 1, siz;

bool dfs(int u) {
	cnt ++;
	if(cnt == k) {
		return true;
	}
	int t[26], sz = ch[u].size(); 
	memset(t,0,sizeof(t));
	F(i,0,sz-1) {
		int p = ch[u][i], v = s[p] - 'a';
		if(!t[v]) t[v] = ++tot;
		if(p<n) ch[t[v]].push_back(p+1);
	}
	F(i,0,25) if(t[i]) {
		if(dfs(t[i])) { ans[siz++] = 'a'+i; return true; }
	}
	return false;
}

int main() {
	scanf("%s%d", s+1, &k);
	n = strlen(s+1);
	F(i,1,n) ch[1].push_back(i);
	dfs(1);
	F_(i,siz-1,0) printf("%c", ans[i]);
	printf("\n");
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:38:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s%d", s+1, &k);
                        ^

Judge Result