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/**
* @brief Codeforces Round #283 (Div. 2) c
* @file c.cpp
* @author mianma
* @created 2014/12/22 13:38
* @edited 2014/12/22 13:38
* @type greedy
* @time cost time O(m*n)
* @mem cost mem 2*MAXN^2 + 2*MAXN
* @note
*/
#include <fstream>
#include <iostream>
#include <cstring>
#include <vector>
using namespace std;
#define max(a, b) ((a) > (b) ? (a) : (b))
#define min(a, b) ((a) > (b) ? (b) : (a))
#define abs(a) ((a) > 0 ? (a) : (0 - (a)))
#define CLR(vec) memset(vec, 0, sizeof(vec))
#ifdef DEBUG
ifstream in;
ofstream out;
#define CIN in
#define COUT out
#else
#define CIN cin
#define COUT cout
#endif
#define MAXN 110
char table[MAXN][MAXN]; /*store input string*/
int record[MAXN][MAXN]; /*record row status */
int status1[MAXN]; /*curr row‘s substring is the same with the prev row*/
int status2[MAXN];
int n, m;
int ans = 0;
int *curr = status1;
int *old = status2;
int main(void){
#ifdef DEBUG
freopen("./in", "r", stdin);
freopen("./out", "w", stdout);
#endif
scanf("%d%d", &n, &m);
for(int i = 0; i < n; i++)
scanf("%s", table[i]);
for(int i = 1; i < n; i++)
for(int j = 0; j < m; j++)
record[i][j] = table[i][j] - table[i - 1][j];
for(int col = 0; col < m; col++){
int fail = 0;
for(int row = 1; row < n; row++){
/*substring is the same with the prev row*/
if(0 == old[row]){
if(record[row][col] > 0)
curr[row] = 1;
else if(record[row][col] < 0){
fail = 1;
break;
}else
curr[row] = 0;
}else
curr[row] = 1;
}
if(!fail){
#ifdef DEBUG
printf("col %d insert\n", col);
printf("bmp new:\n");
for(int j = 1; j < n; j++)
printf("%d ", curr[j]);
printf("\n");
#endif
int * tmp = curr;
curr = old;
old = tmp;
++ans;
}
}
printf("%d\n", m - ans);
return 0;
}
Codeforces Round #283 (Div. 2) c
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原文地址：http://my.oschina.net/u/572632/blog/359174
