UVA 1625 Color Length DP

#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <set>
#include <vector>
#include <string>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <cstdlib>
#include <climits>
#include <cmath>
#include <ctime>
#include <algorithm>
#include <stack>
#include <sstream>
#include <numeric>
#include <fstream>
#include <functional>

using namespace std;

#define MP make_pair
#define PB push_back
typedef long long LL;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef pair<int,int> pii;
const int INF = INT_MAX / 3;
const double eps = 1e-8;
const LL LINF = 1e17;
const double DINF = 1e60;
const int maxn = 5005;
int n,m,f[maxn][maxn];
char str1[maxn], str2[maxn];
int scnt1[maxn][26], scnt2[maxn][26];

int main() {
int T; scanf("%d",&T);
while(T--) {
scanf("%s%s",str1 + 1,str2 + 1);
int len1 = strlen(str1 + 1), len2 = strlen(str2 + 1);
memset(scnt1,0,sizeof(scnt1));
memset(scnt2,0,sizeof(scnt2));
for(int i = 1;i <= len1;i++) {
int nc = str1[i] - 'A';
for(int j = 0;j < 26;j++) {
if(j == nc) scnt1[i][j] = scnt1[i - 1][j] + 1;
else scnt1[i][j] = scnt1[i - 1][j];
}
}
for(int i = 1;i <= len2;i++) {
int nc = str2[i] - 'A';
for(int j = 0;j < 26;j++) {
if(j == nc) scnt2[i][j] = scnt2[i - 1][j] + 1;
else scnt2[i][j] = scnt2[i - 1][j];
}
}
for(int i = 0;i <= len1;i++) {
for(int j = 0;j <= len2;j++) {
f[i][j] = INF;
}
}
f[0][0] = 0;
for(int i = 0;i <= len1;i++) {
for(int j = 0;j <= len2;j++) {
int npos, nc, ccnt, zcnt;
if(i < len1) {
npos = i + 1 + j, nc = str1[i + 1] - 'A',
ccnt = scnt1[i + 1][nc] + scnt2[j][nc],
zcnt = scnt1[len1][nc] + scnt2[len2][nc];
if(ccnt == 1) {
if(zcnt == 1) f[i + 1][j] = min(f[i + 1][j], f[i][j]);
else {
f[i + 1][j] = min(f[i + 1][j], f[i][j] - npos);
}
}
else if(ccnt == zcnt) {
f[i + 1][j] = min(f[i + 1][j], f[i][j] + npos);
}
else f[i + 1][j] = min(f[i + 1][j], f[i][j]);
}
if(j < len2) {
npos = i + 1 + j;
nc = str2[j + 1] - 'A';
ccnt = scnt1[i][nc] + scnt2[j + 1][nc];
zcnt = scnt1[len1][nc] + scnt2[len2][nc];
if(ccnt == 1) {
if(zcnt == 1) f[i][j + 1] = min(f[i][j + 1], f[i][j]);
else {
f[i][j + 1] = min(f[i][j + 1], f[i][j] - npos);
}
}
else if(ccnt == zcnt) {
f[i][j + 1] = min(f[i][j + 1], f[i][j] + npos);
}
else f[i][j + 1] = min(f[i][j + 1], f[i][j]);
}
}
}
printf("%d\n",f[len1][len2]);
}
return 0;
}